make sanity and iozone run from llite over the lov in the new ocp

make sanity and iozone run from llite over the lov in the new ocp
io model.
- add ocp_off to the ocp so the lov can remap it as it passes through
- fix up the page accounting a bit 'cause truncate doesn't really know
  right know to subtract pages from the dirty or io counts
- pass our completion struct, _not_ a pointer to the complete function
- make sure to always free the ocp in commit_write_sync
- disable the watermark io until it actually does something
- make sure to alter the filehandle/o_id as we pass through the lov
- initialize our loi bits in lov_unpackmd