Lightweight Java Game Library Code

Linux: Fixed resetDisplayMode in case XRandr is used and the first reported mode is not the initial mode

Linux: don't throw exception if Xrandr or XF86VM extension query fails

Linux: Added -lm and -std=c99 to fix the warning abount round(). Removed some unnecessary headers

Linux: More native code refactoring

Linux: Removed current_* mode cache from display.c

Linux: Removed getScreenModeWidth/Height from display.c

Linux: fixed an issue with Xrandr timestamps

Linux: let exceptions from display.c propagate to LinuxDisplay.java

Linux: Moved saved display mode from C to LinuxDisplay.java

Linux: Moved some JNI functions