Merge pull request #240 from erwincoumans/master

allow to compile using gcc-4.x on Mac OSX
AMD 14.50Alpha5 driver fixes the issue with MPR kernel, re-enable testFileFracture.bullet
call 'updateCamera' in GpuDemos.
Add serialization support for btGeneric6DofSpring2Constraint
Attempt to re-order serialization data so it can be serialized in-memory (for deep copy)
Update btSerializer.h

fix compile error in LinearMath/btSerializer.h
minor cleanup of btgui/demo3 stuff, much more demo cleanup is needed
moved some files in btgui/Bullet3AppSupport
Merge pull request #243 from erwincoumans/master

minor cleanup of btgui/demo3 stuff, much more demo cleanup is needed
split Wavefront .obj to graphics conversion in a reusable file (Wavefront2GLInstanceGraphicsShape.*)
Merge pull request #245 from erwincoumans/master

split Wavefront .obj to graphics conversion in a reusable file (Wavefron...
add btInMemorySerializer (experiments, allows for in-memory deep copy of worlds, bypassing the BulletFileLoader mechanism)
add btCollisionWorldImporter that can load a .bullet file, or use the btInMemorySerializer for deep-copy
Merge pull request #246 from erwincoumans/master

add btInMemorySerializer (experiments, allows for in-memory deep copy of...
disable btInMemorySerializer by default
Merge pull request #247 from erwincoumans/master

disable btInMemorySerializer by default
fix btInMemorySerializer
disable btInMemorySerializer by default
fix CMakeLists.txt on Mac/Linux when using BUILD_SHARED_LIBS
refactor to allow various gfx backends (work-in-progress)
enable OpenGL3 by default (part of work-in-progress refactor)
fix max osx build
Merge remote-tracking branch 'upstream/master'