need to add streaming because memory is too small to store all lines
initial test of PD control in physics server, need to switch to PD control for motor constraint, instead of using external forces.
store command-line arguments in bulletDemo.txt
save/load of configuration, save demo name instead of index
add setBackgroundColor as example (background_color_red) and
mouse move/wheel speed config (mouse_wheel_multiplier and mouse_move_multiplier)
(saved after changing the demo)
default btIDebugDraw colors can be changed
b3CommandLineArgs::GetCmdLineArgument returns bool, and b3CommandLineArgs::addArgs added
fix copy/paste
use DIRECTLY_UPDATE_VELOCITY_DURING_SOLVER_ITERATIONS by default for now,
until we find the issue with some failing test cases in btMultiBody
fix a crashing issue in MyMultiBodyCreator.cpp (uninitialized variable)
disable excessive debug printf in URDF2Bullet
add example description for all examples (with word-wrap)
add the VoronoiFractureDemo, note that the collision are disabled after breaking constraints.
add optional GwenOpenGLTest, to make it easier to see Gwen user interface features.
