#71: create export2thredds in Nansat.
Merge branch 'develop' of https://github.com/nansencenter/nansat into issue71
#71: if get_time() in Nansat.export2threds() is None, delete from the list.
#issue71: replace 'FillValue' to '_FillValue' in Nansat.export2thredds()
#71 Modify ncep mapper. ncep files bofore Jun.2008 are possible to read.
minor update of mapper_globcolour_l3m
#71 fix few things in Nansat.export2thredds
Merge branch 'issue71' of github.com:nansencenter/nansat into issue71
Merge branch 'develop' into issue71
Merge remote-tracking branch 'origin/develop' into akorosov/evelop
Merge branch 'issue71' into develop