Bug-fix: correct MPIR_proctable setup when we use wraparound ranks.

As reported by John DelSignore @ Roguewave, when we wraparound ranks
among nodes, we were not allocating the MPIR_proctable structure in
rank order.  We were always grouping them per node.

Reviewed by dinan.
Fix req. op. completion outside of PT epoch

This is a temporary fix for request-generating operations to allow their
requests to be completed after the user has called unlock on the given
target.  This closes ticket #1801.  Ticket #1741 is still active and is
keeping track of the fact that an implementation of req. ops that tracks
and completes individual operations (rather than the current approach,
which just calls flush) is still needed.

Reviewer: goodell
Add additional wait/test cases to Req. ops. test

This adds additional cases to the request-generation RMA operations test
case that ensures the implementation correctly handles waiting on the
request inside of the same passive target epoch, a different passive
target epoch, a different fence epoch, and no epoch.

Reviewer: goodell
Fix Irecv race in wait/test_all/any/some err tests

This fixes a race in the ERR_IN_STATUS tests for wait/test_all/any/some
tests.  In these tests, there was a race that could cause the tested
error to occur within the Irecv call, rather than the wait/test call
(expected behavior).  This race was happening when MPICH_ASYNC_PROGRESS
was enabled.  It should be noted that tests tests still rely on
non-standard behavior, in particular some/any calls are expected to
complete all operations.  This closes ticket #1802.

Reviewer: balaji
Replace calls to sleep with MTestSleep in tests

This replaces calls to non-portable (to e.g. Windows) sleep with calls
to MTestSleep.  Submitted by Jeff Hammond.  Where possible, dependencies
on unistd.h have been removed.

Reviewer: dinan
Fix coll6 test hanging with more than 10 processes

This closes ticket #1798.  Patch provided by Jeff Hammond.

Reviewer: dinan