add UDP network connection for physics client <-> server.
also set spinning friction in rolling friction demo (otherwise objects may keep on spinning forever)
only allow server to create and initialize shared memory,
client will report failure
intercept signals to cleanup shared memory in standalone app, thanks to
Roland Philippsen.
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
