Putting the code into shape for major changes in the spatial interpolations as well as pushing the minor version nunmber up

Lots of vectors copies were made using push_back(). This is definitely not efficient! This has been replaced by vec_o = vec_i, we will see which impact it has on performances...

Porting Nander's implementation of Thomas algorithm (solver for tridiagonal matrix) to the matrix class

Still tracking a stupid bug somewhere between meteoio, snowpack and alpine3d... Trying to remove some unecessary stuff

fixing some of the warnings found on Hera (sorry for not noticing before). All the size_t / unsigned int stuff will have to be addressed later

The A3DIO plugin was not properly reading data, this has been fixed. Some warnings have been turned off for osX (signedness and 32/64 bits because of size_t since we will have to redo all our indices to make they consistently rely on size_t)

Trying to get rid of a pointer bug in A3DIO: the ifstream object does not need to be a class member (ie reducing its scope), simplifying some calls...

My previous commit was terrible... it simply made it impossible to define optional keys. This has now been fixed but required a change in the API. So, don't use Config::nothrow but IOUtils::nothrow instead.

The "nothrow" option was not properly forwarded in Config, leading to unnecessary throw/catch. The sun.cc example was set to executable.

Fixing the indentation in libsmet and fixing the (very annoying) warnings in MathOptim.h. The cubic root optimizations have been tested and work as advertized (~3 times faster, largest relative error 1.2e-4).

This is a fix for Snowpack issue 291 : on Windows, when the file would stop right after [DATA} (ie without even a new line), the data section pointer would be invalid (set to -1) but a getline on it would not set eof and therefore the reading loop would never end... So if the data section pointer is -1, we simply return (there is obviously nothing to read).

In order to try to be closer to the spirit of the STL, now the empty strings/vectors/lists are tested with .empty(), the first/last elements of vectors accessed with front()/back(), the empty strings are not contructed with string("") but with string(), etc This makes a benchmark based on meteo_reading ~4% faster and this makes the code suprisingly easier to read. 

Some extra constification took place as well as some minor code cleanup (optimizing the comparison between two vectors in order to perform less tests, etc).

The Date class can now properly generate and parse full ISO timestamps, including time zone information. The full specification is now supported by convertString() with a helper method in the Date class. Ouputing an ISO string with its time zone is done by requesting the ISO_TZ format.

Now, when libsmet attemps to write a station that does not contain any data, it will complain but will not throw an exception (otherwise when working with large numbers of stations, the odds of getting an exception are too high). An implementation for fast cubic root is now part of Optim, but still has to be tested. Some code cleanup (using .empty(), using copy constructor instead of construct+copy) occured in IOUtils.

Truncating the path+file down to file only for exceptions was not working on Windows (since the path delimiter is '\' instead of '/')

Lots of small fixes after running cppcheck on Windows: unused variables, use ++i instead of i++ for complex types (ie mostly iterators for us) for more performance, a few variables that could be passed as const&, use vector.empty() instead of vector.size==0 (for clarity and potentially performances).

The plugins used to keep a reference to a config object as provided by IOManager. But this was triggering some warnings (reference to an object that might disappear outside of the constructor), therefore it has been replaced by a const copy (it is not yet 100% sure if this is really better, but at least the compilers won't complain).

When a user was provinding IMISIO with a non-existing station name, the error messages were quite cryptic. In order to properly tell the user what happened, the code has been slightly reorganized. Some code clean up also took place in IMISIO.

All the "#ifdef(_WIN)" have been replaced by "#ifdef(WIN)" for consistency. The message box code for Windows and osX has been reorganized, the console messages are now better colorized and the backtrace comes before the error message itself.

On osx too, the exceptions can now produce a message box. Several warnings have been fixed (mostly signed/unisgned issues)

When calling the what() of an exception on Windows, it now shows the message in a dialog box as well as printed in the terminal

The estimation of the average sampling rate was quite wrong: it was not correct for multiple stations or for partially empty buffers (ie giving an end date way beyond the real end of the data). It was also claiming to return a value in 1/s but instead it was 1/days. This now only takes into account the time interval when there is some data and properly handles multiple stations and returns a value in Hz (or 1/s). The documentation has been expanded. Also some code cleanup (constification).

Bugfix in libinterpol1D.cc: "if (in_X.size()>0) B=in_X[1]" should read "if (in_X.size()>0) B=in_X[0]"

The reason for the non-functionning popc version has been found: we have to manually set the cxx compiler to popcc.

Some better error messages have been added to SMETIO as well as some code cleanup. Some comments have been added to IOManager, and missing popc code added to DEMObject and Date.

The detection of popc has been improved, the ARC plugin can now handle empty lines in the data section (since some versions of ArcGis produce such files) and the exceptions now remove the full path in front of the source file name when reporting the source code location of an exception (so the users would be less confused by this Desktop\Bavay\etc).

A new example has been added, to show what can be done with grids. The popc version was broken, this has been fixed.

Added an extra error message in ImisIO and a new method for Config: keyExists() to check if a given key is present (instead of always reading a key with nothrow, etc)

Deleting the NROFSTATIONS from the example io.ini since this key is not used anymore and missleading...