Readrecordlock changes:

Readrecordlock changes:

Make the use of ctdb_release_lock() mandatory from the callback.

Split ctdb_release_lock() in two, release the tdb lock in the
ctdb_release_lock() function and move the freeing of the lock structure to ctdb_free_lock() which is private to libctdb.

When the callback returns, verify that the callback has actually released the lock and warn (FIXME) if not.

Update ctdb_writerecord to warn and fail (FIXME) if writing while the lock is not held.