This patch is the preliminary work needed for the kernel's first IPC API: the
Zambesii Asynchronous IPC API; or ZAsync for short. I've also done some cleanup
work around the tree.

Also added a constructor to messageStreamC::headerS which has significantly
reduced code duplication for message initialization all around the tree.

* memReservoir:
  * Enhanced portability of some pointer manipulation.
  * Removed an obsolete type.
* New error code: ERROR_DUPLICATE, used to signify that an operation could not
  be completed due to a duplicate resource being found.
* Timer Stream:
  * Updated prototypes for the oneshot APIs to match the kernel's general API
    argument ordering.
  * Unified the request and event message structures into one (timerMsgS).
* Process Trib: New function: getThread(): directly looks up a thread ID.