Added better error message when input file argument is not given.
Added acceleration arrow.
Update footprint tests (yes they fail)
Merge branch 'master' of github.com:golems/hubomz
Update footprint tests
More testing and bugfixing in footprint

Also, tests pass now
halfway through rebuilding zmpdemo.cpp
Merge branch 'master' of github.com:golems/hubomz into integration

Conflicts:
	zmp/footprint.cpp
	zmp/zmpdemo.cpp
zmpdemo uses the walk generator now and compiles nicely.

the walk generator... doesn't. Have fun! :P