New transno regimen:

New transno regimen:
  - no more transno semaphore: the LDLM is the one true source of concurrency
    control
  - allocate transnos and log requests for failed requests too
  - record request status and open-disposition in last_rcvd as well
  - mds_finish_transno commits the handle, if there is one (and creates its own
    for the last_rcvd update, if needed).

Much nicer (IMO) error-handling in mds_reint.c and such.  At the least, 85%
fewer gotos.

Rename "last_rcvd" to "(last_)transno" in various places, because it's clearer
that way (again, IMO).

Warning (type mismatch) fixes in osc_request that were bugging me.