Staging: pohmelfs: inode operations.

This is the main patch which implements inode operations
(like reading and writing) and superblock processing
(filesystem registration, initial autoconfiguration
with the server like permissions, size of the exported
dir, amount of the objects created and so on).

POHMELFS relies on system's writeback cache mechanism
shown here, as long as cache coherency protocol described
later.
Signed-off-by: NEvgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>