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. 
for an analysis object, we are prototyping the following attribute pattern --

Analysis.settings
Analysis.features

i think wing will fit into features,
and the spacing parameters there might fit into settings