VFD SWMR RFC. Updates on the RFC are cursory, and mostly in the
introduction. The design section is dated -- added a warning to
this effect.
Reviewed and editied the users guide -- specifically:
Verified instructions for build and test, and also for demos.
Removed mention of call to autogen.sh, as that will already be
run on the friendly user release version.
Re-worked the introduction to better discribe VFD SWMR, and
to outline current limitations.
Changed references to "shadow file" to "metadata file" to match
field names.
Still need to update pointer to the bit-bucket repository for the
friendly user release.
Also, must verify that the demo code mentioned in the user guide
is publicly available.
In the `vfd_swmr_create_fapl()` dissection, change the /** **/
comments in the literal code to plain markdown paragraphs.
Slightly change wording and markdown elsewhere.
