WINGs: Add W_KeycodeToKeysym to replace XKeycodeToKeysym/XkbKeycodeToKeysym calls
XKeycodeToKeysym was deprecated some time ago and we replaced
those function calls to XkbKeycodeToKeysym.
Usage of XkbKeycodeToKeysym is not the best as it appears
the XKEYBOARD can be disabled via xorg.conf (at least on Linux).
So just replacing XKeycodeToKeysym() with XkbKeycodeToKeysym()
could cause run-time errors on top of the compilation warning
we may have.
Better fix is to address the problem without introducing a
dependency on XKEYBOARD. W_KeycodeToKeysym is the equivalent
code for XKeycodeToKeysym/XkbKeycodeToKeysym using
XGetKeyboardMapping instead.
As a new function is added to the library WINGs library version
is bumped.