Move Shape::computeInertia() into public methods
Add local inertia matrix mI to BodyNode.

W/r/t commit, mI is not used in any calculations.
Use mI in BodyNode's internal calculations.
Add local/world get/set to BodyNode's inertia.
Sub Shape::setInertia w/ BodyNode::setLocalInertia

Shape::setInertia() is now unused.
Replace Shape::getInertia with BodyNode equiv.
Remove inertia matrix from Shape
Fix CoM assignment bug in ParserSkel.cpp

Within the context of one BodyNode creation function, Shape dimensions
were used as Shape offset. CoM should be used as Shape offset for DART
graphics parsers.
Replace Shape mass calls with BodyNode equiv.

Shape calls that set mass have been replaced with BodyNode::setMass()
calls where appropriate.
Remove mass from Shape
Rename BodyNode mShape to mVizShape
Add getVizShape() and replace appropriate calls
Add mColShape to BodyNode
Fix type checking in CollisionSkeletonNode()
Replace get/set Shape with get/set Viz/Col Shape
Remove colMesh from Shape

BodyNodes now use mVizShape and mColShape to as separate entities to
handle rendering vs. collision detection. All collision mesh logic has
been delegated to mColShape.
Merge branch 'master' into eric/shape-refactoring