btrfs: btrfsck is now actually the same binary as "btrfs"
symlinked to save space.
filesystems: add priority option for swap devices.

Useful for setting up raid0-like load balancing for swap.
By giving multiple swap devices the same prio.
kde4: use udisks2 for kde versions that support it.

Currently, none do, although kde 4.10 is supposed to be able to use it.