Merge branch 'issue67-srs-input' into develop
Ad try/except to Domain.__repr__ for supressing error when georeference of the source is not known
#38: fix bug with subVRTs being a dict in VRT.__init__(). That caused VRT objects to share subVRTs and generated troubles when adding bands with same name to several Nansats
Created initial version of mapper for Sentinel-1 level-2 data.
Merge branch 'develop' of https://github.com/nansencenter/nansat into develop
Small: obpg-l3 use NSR(); Sigma0HHToSigma0VVFunction doesnt call RawcountsIncidenceToSigma0Function
Add mapper for AMSR2 L3B north pole
Cleanup of ASAR mapper and corresponding Envisat class/module (by/with Anton). ASAR now adds incidence angle through new mechanism, going through small Nansat object.
ASAR mapper now calculates and stores SAR look direction, available as lazy operation on small ADS array
Fixed bug in ASAR/MERIS helper class Envisat: modifying hardcoded list of units affects subsequent calls to get_array_from_ADS function
ASAR mapper now generates incidence angle and SAR look direction through small internal Nansat object, reprojected onto full ASAR domain. Takes care of wrapping problem around 0-360 degrees for SAR look direction.
Added last edit of ASAR mapper from issue57-sar-azimuth
Revert "Added last edit of ASAR mapper from issue57-sar-azimuth"

This reverts commit 368bdef20808311a104a902055dba39039d8e5d3.
Revert "Fixed bug in ASAR/MERIS helper class Envisat: modifying hardcoded list of units affects subsequent calls to get_array_from_ADS function"

This reverts commit 44d985561c036f5e4517f2a79a1850a05a07e9e7.
Revert "ASAR mapper now calculates and stores SAR look direction, available as lazy operation on small ADS array"

This reverts commit 74e6d5ea7f98dbc91149f9b9e6288e321e03e45c.
Revert "Cleanup of ASAR mapper and corresponding Envisat class/module (by/with Anton). ASAR now adds incidence angle through new mechanism, going through small Nansat object."

This reverts commit 32f5110b64d30c2f880fe84deedfb3ade282f79c.
no debugging...
validValues were never user in function pcolormesh. Added **kwargs to be able to use vmin and vmax (+other) keyword arguments instead
Improved performance of calculation of incidence angle and SAR look direction, by avoiding Nansat.add_band() which created chain of VRTs, each requiring evaluation. Also using now vrt.get_resized_vrt() which seems to be more accurate than Nansat.reproject()
Radarsat2-mapper now adds band with SAR look direction, using same method as ASAR mapper.