Add OPENSURGSIM_DATA_DIR to the exported variables

This way other application can get access to the default shaders
VisualTestCommon links to correct glut library.

With target_link_libraries, the various VisualTests do not need to
link to glut or include the glut header directories.
Rename 'CollisionShape' to 'Shape' when serializing RigidCollisionRep

Revise UnitTest
Fix path on linux
Install Data into install target
Add external force/stiffness/damping accessors in DeformableRep

This is to be compliant with the RigidRep API
Fix filename FemRepLocalizationTest.cpp to Fem3DRepLocalizationTest.cpp

This file is testing the Fem3D localization...it was wrongly named.
+
quick clean up
Remove globalPosition member from Collision::Location

- Reason: The globalPosition calculated by the Dcd becomes irrelevant when the Representation's pose is updated. And the Representation's pose is updated twice within PhysicsManager::update(). In free motion and push results step. Since the Dcd is called between these two, the contact info is stale outside of the PhysicsManager. So, the globalPosition is replaced with rigidLocalPosition.
- Updated all DcdContact::doCalcluateContact() functions and unit tests.
- Updated other part of the code which were broke because of this (VisualizeContactBehavior, RigidRepresentationTest)
- Updated StaplerBehavior::createBilateral3DConstraint to accept
  Collision::Locations for both the representations.
Add Fem1DRep/Fem2DRep Localization + UnitTests
Implement Fem1DRep/Fem2DRep addExternalGeneralizedForce + UnitTest
Merge branch 'master' into fix/remove-globalposition-from-dcd
Add specific linux data directory
Fix cmake syntax error
Different Path for Data install directory
Merge branch 'fix/remove-globalposition-from-dcd' into 'master'

Remove globalPosition member from Collision::Location

+1: Julien Lenoir, Harald Scheirich, Ryan Beasley, Paul Novotny

Merged-on: https://www.assembla.com/code/OpenSurgSim/git/merge_requests/1073543
Merge remote-tracking branch 'origin/master' into fix/RigidCollisionRepresentation-Serialization
Merge branch 'fix/RigidCollisionRepresentation-Serialization' into 'master'

Revise RigidCollisionRepresentation serialization

Merged-on: https://www.assembla.com/code/OpenSurgSim/git/merge_requests/1066083
Merge branch 'fix/visualtest-glut-linking' into 'master'

Fixes the VisualTestCommon CMakeLists linking to glut.

+1: Julien Lenoir, Harald Scheirich, haizhouW

Merged-on: https://www.assembla.com/code/OpenSurgSim/git/merge_requests/1065933
Clean all Fem based doCalculatePosition method
Clean up all Fem based addExternalGeneralizedForce

ASSERT on all parameters (nullptr and expected sizes)
But do not need to assert on further information contained inside the Localization (index/coordinate), the Localization class took care of that part.
Clean up all Fem based Localization doxygen doc