Update the AUTHORS file
Update the version number for v0.2.3.
Rename MPI{Matrix,View} to Xchg{Matrix,View}.

This will avoid confusion when we start using them to exchange
data with the host rather than just other MPI ranks.
Unify some of the packing kernels between backends.
Include the clBLAS status code when raising.
Cleanups.
Cleanups.
Add support for surface anti-aliasing.  Cleanups to follow.
Cleanups.
Whitespace.
clean up roem

roem cleanup

RoeM Cleanup #2

RoeM Cleanup #3

RoeM Cleanup #3