By setting "indent-tabs-mode:nil" we should hopefully begin to slowly
squeeze out hard tabs from the source without a disruptive (to
downstream projects) whitespace-fixing change.

No reviewer.

No reviewer.

Reviewed by buntinas.

Adds implementation of atomic fetch-and-op operation and several test cases.

Reviewer: buntinas

Reviewer: buntinas

This patch adds support for the new MPI-3 compare-and-swap routine.  The
implementation embeds the data into the packet header to reduce the number of
messages.

Reviewer: buntinas

Pulled bit manipulation arithmetic into macros for converting handles to
indices in MPIR_Op and MPIR_Op_check_dtype function pointer tables.

Reviewer: buntinas

This is an first step in implementing MPI_Get_accumulate.  Currently, only
communication with self is supported.

Reviewer: buntinas