The bulk of the remaining renaming changes, in one final glorious "blob". Thanks to Jeff for some help chasing down a few spots. Per chat with Jeff, we decided to cleanup a few things that were historical in nature:

top_ompi_srcdir  ->  OMPI_TOP_SRCDIR
top_ompi_builddir -> OMPI_TOP_BUILDDIR

We also split the srcdir/builddir flags according to their local tree (e.g., OPAL_TOP_SRCDIR), and tied them all together in configure.ac. Renamed ompi_ignore and ompi_unignore to be opal_<foo> as these are agnostic markers.

Only thing left is ompilibdir being treated similar to what we dif for srcdir/builddir. Coming soon.