add Lua and basic Lua->C/C++ integration test, in preparation for Bullet demos setup using Lua scripts.
added very crude little LuaDemo, to create physics objects using Lua scripts (very preliminary)
batching reports the size of the batches, and solver uses this as termination condition, giving a good speedup
move OpenCL initialization for the unit tests in a shared header file, and support some basic command-line arguments
--cl_device=1 --cl_platform=1 --allow_opencl_cpu
add chaindemo, test for mass ratios
restore sleeping/activation mode in featherstone demo
Use _VARIADIC_MAX=10 to avoid Google Test issues with Visual Studio 2012, thanks to Mobeen for the report
Enable verbose printf for unit tests
add ChainDemo.cpp
create some demos to compare MLCP solvers
Draft Parallel Linear BVH Broadphase.
Use merged AABB to calculate grid cell size for PLBVH.
Fix PLBVH reduction kernels, simplify nodes per level calculation.

Also calculate index ranges for each internal node.
Accelerate GPU raycaster with PLBVH.
Properly propagate the applied impulse for the MLCP solvers, so it will be available for contact and non-contact constraints.
Use real-time clock in AllBullet2Demos, rather than hard-coded 1./60.
btMultiBodyConstraintSolver writes back the applied impulse for contact points
(added some debugging output for this in the demos, commented-out by default)
Various minor PLBVH related changes.

-Use most significant bit instead of negative for internal nodes.
-Explicitly store root node index, so that it does not have to be 0.
-Check the root node first in PLBVH traversal.
-Fix rigid body clipping in RaytracedShadowDemo.
Fix PLBVH with 0/1 nodes, fix optimized ray-AABB intersect.
Split PLBVH files into .h/.cpp.

Also move PLBVH binary tree construction into separate function.
Add only small AABBs to PLBVH, add large AABB support.
Draft PLBVH construction using binary radix tree.
fix make install, when using CMake
see Issue #41
fix CMake build
w
Merge various commits into a single commit.

Commits after:
2014-03-03 Draft PLBVH construction using binary radix tree.
f19f85368517ff08a4f329710a1710f547c545d2

Are merged into a single commit; this includes:
03-10 Remove single launch build AABB kernel.
03-10 Add kernels for setting PLBVH AABBs using distance from root.
03-10 Use faster morton code, remove convertChildNodeFormat kernel.
03-09 Add duplicate morton code handling to binary radix construct.
03-09 Remove slower PLBVH constructors.
03-08 Add binary radix tree construct using binary search.
03-06 Remove slowest PLBVH constructor, fix implicit construct AABB.
03-04 Test various optimizations for PLBVH binary radix tree construct.