Fix dynamics update for immobile skeletons
Clean up SdfParser.cpp
Add contact forces to each body node as external forces. This is for correct joint force/torque sensoring.

This is not a long term solution.
Fix typo.
Fix applying constraint force to body nodes
Merge branch 'origin/contact_force'
Fix alignment bug introduced in 01362db6d0bad3ddc1e9b7a7b2445531f33b2a99
Make use of CMake's target export functionality
Remove FCL from public header files
Merge branch 'origin/master'