Removing the approximated solar radiation daily sum, since it contains a projection error (it seems to project twice to the horizontal)

Finally, another method for handling daily sums of solar radiation has been implemented: when a point is requested, the potential solar radiation is computed for the whole day with a 20 minutes resolution, filling a vector and computing the daily sum. This enables to compute the loss factor. When another point within the same day is requested, the radiation is interpolated from the values stored in the vector and multiplied by the loss factor. Tested on WFJ data, this works very well (of course, days that experience large cloudiness variations are not reproduced well but at least the average flux is correct).

A typo has been fixed in the documentation of Date. 

Now the dates can be rounded to the day (there was a bug preventing it before). A new parametrization has been implemented in SunObject that computes the daily sum of TOA radiation. This is used by a new resampling method that computes subdaily values out of a daily sum of radiation. This is not yet doing such a great job, but this is a start...

Since Rob has committed his precipitation spatial interpolation, the 2D_interpolation reference result had to be updated. Several members in filter classes could be made const/static/private.

Slightly improved documentation on spatial interpolations and now really allowing linear regression on only 2 points

Some headers were not included and the header files were not listed in any kind of convenient order... This is not fixed (find meteoio -name "*.h" | sort gives the order we follow)

Redesigned algorithm for redistribution of solid precip on steep slopes. This is done by pushing precip from the top to the bottom of the slope.
Curvature correction has been turned off. Now this redesign will be validated with laser-scanner data. 

The info string for the spatial interpolations was not being cleared between calls, leading to ever increasing content... Otherwise, using an ostringstream instead of stringstream in PNGIO and fixed a typo in the documentation.

More size_t fixes (ie trying to be consistent) and a bug was found when spatially interpolating using a few specific algorithms that would not reset their internal vectors between two calls (thanks Matteo for helping uncover this bug!)

Some "TODO" have been removed, a missing check has been added in Interpol1D:linRegression (at least 2 valid points are required), type inconsistencies have been fixed in FilterTukey and ProcessinStack. However using size_t for the meteo parameter index is not necessarily a good idea and this will require a careful review.

Finally trying to address the unsigned int vs size_t issue... All index, etc that should be size_t have been made size_t in the data classes.

More changes, according to "Using OCCI: best practices - An Oracle White Paper - May 2003". Now the same Statement object is used accross multiple querries (to reduce memory reallocations).

Data prefetching is now turned ON in Oracle querries, leading to a x2 speed up (global speed up measured on data_converter)

A new test has been created to cover basic statistical functions on vectors. Two bugs have been found and fixed when computing the derivative on a vector of data (the right derivative was in fact a left derivative and the case of X containing nodata was not covered).

Documentation fixes in libinterpol2D and ResamplingAlgorithms. The cmake macro for finding MeteoIO now looks first in the home directory of the user on Mac (as is done on Linux).

Now the toString() method of Meteo2DInterpolator works with the new structure and is called by IOManager.toString(). Small cleanup (white spaces, etc) in 2D_interpolations and ResamplingAlgorithms.

Finally, here we are: the spatial interpolation algorithms are constructed only once and remain as long as the Meteo2DInterpolator remains (generally, as long as IOManager remains). This means that an interpolation algorithm can now keep its own copy of whatever data it wants (for example, dem) to tweak it between calls.

One more step closer to the goal: the dem is now only passed when calling calculate() and the simpleDEMWindInterpolate now computes the curvatures if necessary.

Small optimizations in IOHandler.

Getting closer to the goal of persistent spatial interpolation objects. There are no "initialize" and "getQualityRating" anymore, the initializations are performed by "getQualityRating". The arguments that used to be passed to the constructors are now split between constructor and getQualityRating. A few hacks will have to be removed: we should be able to get rid of some of the callbacks, the plain copy of Date and Dem will have to be avoided (most probably by working with pointers) and the map of objects that has been implemented (but commented out) will be enabled. So, a few hacks remain, but this is already a nice, big step forward!

The median calculation bug had been impacting some other things as well... Some other values were also wrong, and it has been so for a while!

The median computations were relying on std::nth_element and wrongly assuming that the output would be sorted. This is non-standard behavior and is not the case with more recent versions of the STL. This has been fixed.

The ProcessingStack constructor has been optimized by using new methods of Config to remove some now redundant code.

The structure of Meteo2DInterpolator has been brought closer to the structure of DataGenerators. More methods are static.

The Config class now has a method getValues() to retrieve in a vector of type T all values whose keys match a given pattern. This makes it possible to retrieve in one call all the Input::STATIONx values even in the case of discontinuous numbering (issue 341) as well as easily get the number of stations declared in io.ini (issue 220). This number of stations is not guaranteed to work (since some plugins don't list the input stations in io.ini) but should guide memory allocation in user code anyway.

A reference has been fixed in Suntrajectory, redundant errort checking has been removed from GeneratorAlgorithms.

A low pass Butterworth filter has been implemented as a tentative answer to issue 308. Unfortunately, this filter has a non-null phase (ie the signal is shifted in time), meaning that for our applications, it is mostly worthless...

A stupid bug has been fixed in SMETIO: the OSWR was not renamed as RSWR anymore. Otherwise, small documentation fixes.

The error message when the units_multiplier and/or units_offset count don't match with the number of fields was not right (wrong count given) and has been fixed. Some variables that could be const are now const in SmetIO

The method to clear the buffers in BufferedIOHandler was not doing everything it should. Some methods in BufferedIOHandler and IOManager have been made const. The issues 117 and 272 have been adressed: the IOHandler now checks that timestamps are unique and in increasing order. This check has therefore been removed from SMETIO.