Cause pfind() not to return processes in the PRS_NEW state. As a result,

Cause pfind() not to return processes in the PRS_NEW state.  As a result,
threads consuming the result of pfind() will not need to check for a NULL
credential pointer or other signs of an incompletely created process.
However, this also means that pfind() cannot be used to test for the
existence or find such a process.  Annotate pfind() to indicate that this
is the case.  A review of curent consumers seems to indicate that this is
not a problem for any of them.  This closes a number of race conditions
that could result in NULL pointer dereferences and related failure modes.
Other related races continue to exist, especially during iteration of the
allproc list without due caution.

Discussed with:	tjr, green