Two bugs that were stopping write_disjoint from passing. First, an awesome

Two bugs that were stopping write_disjoint from passing.  First, an awesome
typo in lov_lock_contains() prevented llite from recognizing a lock cancelation
associated with the furthest cached region of a file.  Second, a comparision in
obdo_refresh_inode() without a complimentary drop of i_size to 0 prevented a
node from getting size updates after a remote truncate.