Fix #33877: Pressure Sensitivity stop after opening User Preferences Window

Issue was caused by opening the same device id twice and closing one of
descriptors on closing window. This used to close device used by other
windows.

Now moved all device-specific code to SystemX11, so opening and closing
happens only once.

git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@53842 954f8c5b-7b00-dc11-b283-0030488c597c