Remove unused lines
Move joint limit setter/getter from Skeleton to Joint.
Add commented Joint::setPositionUpperLimit() and ...LowerLimit()
Add setting joint position at SkelParser.
Add simple unit test for joint position limit.
Merge branch 'origin/master'

Conflicts:
	src/dynamics/Skeleton.cpp
Merge branch 'origin/master'
Set joint limit enforcement option in Joint.
Remove commented out functions.
Merge branch 'origin/master'

Conflicts:
	src/constraint/ConstraintDynamics.cpp
Fix compiler error due to the last merge.
Set enforcing joint limit as default.
Remove unnecessary lines.
Merge pull request #90 from dartsim/joint_limit

Move joint limit set/get functionality from Skeleton to Joint