Documentation/filesystems/00-INDEX: updates

Add the following documentation-files with description :
 -autofs4-mount-control.txt
 -btrfs.txt
 -debugfs.txt
 -devpts.txt
 -fiemap.txt
 -gfs2-glocks.txt
 -gfs2-uevents.txt
 -omfs.txt
 -path-lookup.txt
 -qnx6.txt
 -quota.txt
 -squashfs.txt
 -sysfs-tagging.txt
 -ubifs.txt
 -xfs-delayed-logging-design.txt
 -xfs-self-describing-metadata.txt

Add the following documentation directories with description :
 -caching
 -cifs (replacing cifs.txt)
 -pohmelfs

Remove the following documentation-files reference:
 -dentry-locking.txt
 -reiser4.txt

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>