Update the chord parameter packing in  in main_wing_planform; added generic fuselage; added new wing geometry calculation classes to compute exposed and flapped wings

update naming to Wing.chords.root and Wing.chords.tip
Apply PEP8 formatting for wing planform files - not sure if these really conform to coding style.
Renamed chord_mid to chord_mid_trap to reflect trapezoidal wing. 
I see the advantage of that approach. And in essence we would just pull the relevant blocks from main_wing_planform. 

A bigger issue is if this approach of sending in the whole object is necessarily the best (it could be). Let's talk about this at review.