Some X11 backend fixes
|Reported by:||SF/gjasny||Owned by:||SF/khalek|
At first #include "common/stdafx.h" was added to compile at all.
Because the closed source ATI driver doesn't support 16bpp I run
my X11 with 24 bit. After starting the backend I got a X11 er
ror. I tracked this down to XShmCreateImage which was
hardwired to 16bpp. Also shmget allocated the wrong amount of
changed it acording to Keith Packards xspec paper. Additionally I
added a check for SHM at all plus some more error checkings.
Ticket imported from: #896094. Ticket imported from: patches/431.