Razer Hydra integration
Change ShapeBase to only test if available meshes

The ShapeBase class tests if all of its meshes are hidden and if so,
then it doesn't render during that frame.  However, if there are no
meshes in the ShapeBase and only nodes then rendering is also skipped.
Unfortunately, this also skips the rendering of any mounted images.
This change allows for a mesh-less skeleton to render any mounted
images.
Merge pull request #236 from DavidWyand-GG/HiddenMesh

Change ShapeBase to only test if available meshes
Compile Bullet library under Windows

For some reason the Bullet physics library's project file was not being
included in the solution when the bullet module was added.  This change
makes sure that when you want to use Bullet, it will correctly be added
by the Project Generator.
Merge pull request #237 from DavidWyand-GG/BulletBuilding

Compile Bullet library under Windows
Merge pull request #234 from DavidWyand-GG/RazerHydraWork

Razer Hydra integration
Updates livVorbis to v1.3.3
Merge pull request #238 from thecelloman/updatelibvorbis

Update libvorbis to v1.3.3
Updates libogg to v1.3.0
Merge pull request #239 from thecelloman/updatelibogg

Updates libogg to v1.3.0
Patches the libvorbis update with missed files.
Merge pull request #240 from thecelloman/vorbispatch

Patches the libvorbis update with missed files.
Bug fixes for alternative zip layout and define to toggle it on
Update squish library to 1.11
Removed hard coded directory paths

- Removed references to core directory.
- Switch some references to tools directory
- Added preferences variables where appropriate
Merge pull request #248 from DavidWyand-GG/HardCodedPaths2

Removed hard coded directory paths
Updating libpng to v1.5.14 and zlib to v1.2.7

Since libpng has a dependency upon zlib, both updates were combined for one commit/pull-request.
Merge pull request #250 from thecelloman/updatelibpngandzlib

Updating libpng to v1.5.14 and zlib to v1.2.7
Merge pull request #243 from thecelloman/updatesquish

Update squish
Merge remote-tracking branch 'upstream/development' into game