Split Recording into header/source files
- Add some comment
- Fix styels
Replace Recording::addSkeleton() to Recording::updateNumGenCoords()

Recording class needs removeSkeleton() since World class can remove any skeleton in the world. However, removing arbitrary skeleton from Recording is not possible because Recording does not store skeleton pointers but just the number of generalized coordinates. Recording::updateNumGenCoords() gets a list of skeletons and update mNumGenCoordsForSkeletons using it.
Remove inverseDyn from apps/CMakeLists.txt
Merge pull request #181 from dartsim/recording

Clean up baking functionality