[rhel5-branch] New version of the gfs support patch and one more

PATCH 1/2 is the same as the previous attempt for the gfs support. However, the previous version had self.check set to 1 that caused problems on reboot because fsck.gfs failed. I believe 0 is the right value here.

PATCH 2/2 adds the unknownFileSystem class that allows us to just comment out the fstab lines with unknown (not supported) filesystem on upgrade. We could just copy such lines, but that may result in non-booting system, because of for example fsck problems (fsck for such filesystem may be not installed or whatever). Ending up in a shell during boot process is a lot worse then fixing the configuration from the running system with all utilities available.

-- Vratislav Podzimek