OSG Representation for Octree
Unit Test and Render Test for OsgOctreeRepresentation
Remove CppLint warnings, add include guard.
Merge branch 'master' into feature/OsgOctreeRepresentation
CMake change for drop templatization in (Osg)OctreeRepresentation.

Also, after changing OsgOctreeRepresentation::setOctree()'s signature
from SurgSim::DataStructure::OctreeNode<Data> to
SurgSim::Math::OctreeShape, 'yamp-cpp' needs to be added.
Remove templatization on (Osg)OctreeRepresentation

Use OctreeShape instead of OctreeNode in (Osg)OctreeRepresentation.
Templatization on OctreeNode has been dropped in OctreeShape by typedef.

Note that OsgOctreeRepresentation::setOctree() accepts a shared_ptr
instead of a const reference.
Since OctreeShape::getRootNode() returns a non-const shared_ptr to
untemplatized OctreeeNode, the const has to be cast away anyway in
OsgOctreeRepresentation::setOctree().
Revise UnitTest and RenderTest for OsgOctreeRepresentation
Merge remote-tracking branch 'origin/master' into feature/OsgOctreeRepresentation
Only build scene graph at first frame.

Code is ugly now.
Needs refactoring.
Use build-in center(), sizes() methods.

Need to move initial OctreeNode location based on initial position.
Clean up code, remove unnecessary methods, add documentation.
Use coordinate of each OctreeNode's center as its hash key.
Add a comment in OsgOctreeRepresentation.
Merge remote-tracking branch 'origin/master' into wip/OsgOctreeRepresentation-buildSceneGraphOnce
Merge branch 'master' into feature/OsgOctreeRepresentation
Merge remote-tracking branch 'origin/wip/OsgOctreeRepresentation-buildSceneGraphOnce' into feature/OsgOctreeRepresentation
Fix Linux VMs build failure
Revise OsgOctreeRepresentation

Use const reference to emphasize OsgOctreeRepresentation will make a
copy of octree passed in instread of sharing it.

Put constraint on that the OSG tree can only be built before wake up.
Revise Unit Test and Render Test for OsgOctreeRepresentation
Add 'const' qualifier to getRootNode() in OctreeShape class