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.

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 This has been replaced by vec_o = vec_i, we will see which impact it has on performances...

The last filters that had not been ported to the new filtering infrastructure have been ported and their documentation updated. All filters now use window specifications (instead of vector of pointers). The misleading filter argument "index" (for parameter type) has been renamed as "param" for all filters. The use of "unsigned int" for looping over vectors has been replaced by "size_t". The old "soft" behavior for the filters has been restored (ie: if not soft, a point that can not be checked by the filter is deleted).

A few more "consts" have been added.

Another fix/enhancement for POPC: the libraries now ends with "popc" in the popc version, as the autotools build was doing.

Windchill and heat index have been implemented in Atmosphere.

Some cleanup in the filters, some code moved to ProcessingBlock, so that elements that are not filters can inherit ProcessingBlock and get all that it needs. A processing element has been implemented to multiply by a given constant, another one to add a given offset and another one to correct precipitation for undercatch.

Some invalid doxygen comments have been fixed in MathOptim.

The "soft" argument was not properly handled by the Min and Max filters, this has been fixed. All filters now properly reserve the vector size that they need, which reduces the number of instruction fetch misses and should (slightly) improved performances. Please try to use vector.reserve() whenever possible!

Performance boost: Redesign of class MeteoData. The individual public double members like tss, ta, rh have been removed and instead of the rather complicated internal representation with the help of std::map and pointers, the MeteoData object now holds all its important information in one double vector (meteo data) and one string vector (parameter names). Thus the overloaded copy constructor could be slashed radically. This leads to huge performance gains, especially when dealing with huge vectors of MeteoData (which are needed for filtering, resampling, etc).

Furthermore the access to the meteo parameters has been simpleified by overloading the operator(), replacing the old .param(size_t index) and .param(string paramname) functions:

MeteoData md;
double ta = md(MeteoData::TA);

OR

double ta = md("TA");

These changes were propagated into all of MeteoIO.

Another commit related to timezones... The Unix date always being in UTC, this has been fixed. The resampling was not using dates in a proper way, this has been fixed. The GSN plugin has also been fixed, it now rounds time to the closest minute (in order to be consistent with our advertised "1 minute time resolution"). A rounding method has been implemented for dates.

The timezone parameter in io.ini is now named TIME_ZONE instead of TZ for clarity. 

Undefined dates should now be fully handled (ie: also in arithmetic).

Finalization of the new filtering infrastructure: speed optimizations (IOManager, MeteoProcessor), clean up

New filter system rolled out with currently two filters up and running: min_max and mean_avg (without the soft option, only left or right centering). The new filter system is built upon processing blocks that take a vector<MeteoData> as input and return a processed vector<MeteoData>. The individual filters are stacked in a ProcessingStack where they are invoked sequentially.