biendli v2, 150 micro fpv quadcopter

this is an improved version of the biendli, a 150 mm micro fpv quadcopter, see http://www.thingiverse.com/thing:1392320
a complete bill of materials can be found there

i made the following improvements:
- landing skids to which a small hd camera (mobius or runcam) can be attached
- hooks to attach the landing skids to the bottom_frame using rubber bands
- an lug to keep the top frame to the fuselage bottom
- bottom fuselage with simplified arms

use an alphagel pad between the landing