Following a few coverity scans, several inconsistencies / potential bugs have been fixed. Since my commit to picojson got merged, the newest version of picojson has been taken.

The PotentialSW filter can now handle RSWR, most of the (useful) constants defined in the Shade and UnventillatedT filters are now in ProcessingBlock (for easy reuse), the Shade filter now has an easier structure (the Sun object can now do internal caching making the external caching such as performed in the filter not needed anymore).

A new filter has been implemented that compares the measured ISWR with the potential radiation. This would filter out stations that are shaded, stations that fill missing data with zeroes, etc

A bug has been fixed: there was a confusion between the mean adiabatic lapse rate and the dry one. Small code cleanup in DEMObject (with a better toString() method), ARPSIO and ProcShade.

Code cleanup: more consistency in the handling of keep/exclude/merge. Better, more explicit error messages.

Now the SHADE filter will use the last valid splitting coefficient if it can not compute one, within 24 hours. When the measured radiation is too low, no correction is applied because it can only be diffuse radiation (at dawn/dusk).

Now multiple stations are properly supported by the SHADE filter (when computing the mask from the DEM)

A bug in the MeteoData::mergeTimeSeries() method has been fixed that was related to the handling of extra parameters. The SHADE filter can now compute masks directly from the DEM, but this has required to propagate the Config object all the way down to the filter. Some minor code cleanup and documentation fixes.

Please notice that the SHADE filter is currently only appropriate for a single station! The most probable use case is to merge different stations into a new location (or to downscale to a new location) and properly mask the radiation by the surrounding terrain.

A new method has been implemented in order to apply a horizon mask to ISWR. This has not been properly tested yet, this will come soon!