contrib: scripts for easy preferred-xorg-versions generation

contrib: scripts for easy preferred-xorg-versions generation

* live.sh generates conf/distro/include/preferred-xorg-versions-live.inc with
  latest versions available at http://xorg.freedesktop.org/releases/individual/
* 7.5.sh generates preferred-xorg-versions-X11R7.5-live.inc with latest
  versions available at http://www.x.org/releases/X11R7.5/src/
* Temporary files are created in script directory and contains info
  about possible version updates, missing recipes (in "date".log) and
  also generated shell commands for copying recipe from older version
  etc (in "date".cmd).