Merges RigidRepLocalization and FixedRepLocalization.

The same code is used to find the global position for a local position
on a rigid representation, whether or not the representation's pose
is fixed.
This commit reduces code duplication.
Remove visibility property from Graphics

Since the concept of 'activity' and 'visibility' is somehow equivalent
on a graphics representation, 'visibility' property is removed from
graphics representations.

When a graphics representation is active, it is visible; when it's
inactive, it's invisible.
Revise comments and update mock objects
RigidRepresentationBaseLocalization ctor calls Localization ctor.
And some cpplint fixes.
Merge branch 'master' into fix/rigidrepresentationbaselocalization

Conflicts:
	SurgSim/Physics/UnitTests/FixedRepresentationLocalizationTest.cpp
Bug fix

When a graphics representation is added to a group, its
activity/visibility should be the combined effects of the group's
activity/visibility and its own activity/visibility.
Merge remote-tracking branch 'origin/master' into feature/graphics-remove-visibility-property
Cpplint and doxygen warning fix
Roll back changes to (Osg)Group
Graphics manager won't check for activeness any more.

Move the responsibility of checking for activeness from
Graphics::Manager::doUpdate() to the derived classes of
Graphics::Representation.
Revise UnitTests
Roll back changes in OsgGroup
Revise documentation
Update serializable stapling demo
Merge branch 'master' into feature/graphics-remove-visibility-property
RigidRepresentationBaseLocalization typedef'd for RigidRep & FixedRep.

This way all the physics representations have a localization type with
a matching name.
Merge branch 'master' into fix/rigidrepresentationbaselocalization
Fix checking for 64 bit build

In the FindNovintHdalSdk.cmake FindSixenseSdk.cmake files, we were
checking if CMAKE_SIZEOF_VOID_P is 64 to determine if the build was 64
or 32 bit. This was used to determine which versins of the SDK libraries
to use. However, this value is not reported as bits, but bytes. So on
64bit systems, CMAKE_SIZEOF_VOID_P is 8. On 32 bit builds, it is 4.
Add convenience function to convert shared pointers and raise exception when the conversion fails
Moves FixedRepLocalization typedef into FixedRep.h (ditto RigidRepLoc)

With this approach, including FixedRepresentation.h will be sufficient
(and necessary) to create a FixedRepresentationLocalization.