Lock profiling and lock order verification, week 9

[Greg Miller]

Accomplishments for the week:

* Implemented pthread_lockorder_begin_np(),
pthread_lockorder_next_np(), and pthread_lockorder_end_np() to
retrieve the lock order graph generated by libwitness
* Implemented pthread_lockorder_reset_np()
* Implemented pthread_lockorder_set_np()
* Implemented pthread_lockorder_bless_np() to ignore ordering
variations for a pair of locks
* Switched from tracking locks by address inside libwitness to
maintaining a set of lock_info structures
* Added default names for locks
* Added pthread_setname_np() to set lock names

This week, I'll be working on test cases for the new libwitness
features and will begin the code to generate the lock profiling and
witness XML data files.