This file contains some design decissions for various things in this branch.

 - Add probes only for locks which are acquired in one functions and released
   in another function. Locks which are aquired and released in the same
   function should be easy to pair in the code, wheras inter-function
   locking is better checked in dtrace.
 - Probes for locks should be fired after locking and before releasing to
   prevent races (to provide data/function stability in dtrace, see the
   output of "dtrace -v ..." and the corresponding dtrace docs).