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