add usage of TPS for (Domain, VRT).transform_points
Merge remote-tracking branch 'origin/develop' into develop
fix bug in Nansat.crop related to wrong estimation of xSize/ySize if lonlim/latlim are partly outside image
remove adding geotransfrom in obpg_l2 mapper
Merge branch 'issue31-mem-leak-obpgl2' into develop
#17 describe how to create nansat from lon,lat,val grids #54 Nansat.crop() returns 0,1,2
#54 Nansat.crop() returns 0,1,2: update docstring
Merge branch 'develop' of github.com:nansencenter/nansat into develop
Merge branch 'develop' into issue57