Deriving the day-solar RGB using pyspectral to derive the 3.9 reflectance
Adduing for "day microphysics" RGB
adding a sun-corrected overview rgb
Support for rgbs using the seviri 3.9 reflectance (pyspectral)
Merge branch '3.9reflectance' into pre-master

Conflicts:
	mpop/channel.py
	mpop/instruments/seviri.py
	mpop/satin/mipp_xrit.py
	setup.py
Bugfix
Merge branch 'pre-master' of https://github.com/mraspaud/mpop into pre-master