removed clip because it is fine to just use numpy method
projection's docs improved
Geodetic => LatitudeLongitude, now relies on PlateCarree.
Factorized globe definitions outside __init__
made class initialization more explicit, with full CF parameters names
py.test crashes...
removed support for from_proj4 which was causing too much issues
(but keep Proj4 class)
debugged multi-dimensional transform
DimArray.iter now work with flatted axes
BUG: cannot index flattened axis (interpreted like multi-index)
doc updated