qa/151 - don't run for 6 days after a timezone change

Strange but true!  pmlogger_daily is doing the right thing, but
this QA test is confused ... simply skip it until things settle
down (the 6 days comes from the test, it is not make believe).
libpcp - fix for pmUnitsStr_r buffer overrun

Since the definition of pmUnitsStr_r() dictates that buflen be at least
60, enforce this on entry.  There is a small ABI change here that in
the event that buflen is too short, pmUnitsStr_r will now return NULL
instead of buf.

Updated the man page.

Added qa/746 to tickle this buglet and prove it is fixed.

Addresses http://oss.sgi.com/bugzilla/show_bug.cgi?id=1068
linux pmda - nfs4 metrics

The indom for server requests for NFSv4 was not being handled correctly.

When nfsd was started and supporting NFSv4, qa/232 was failing because
pminfo -f was not returning the last member of the instance domain.
Merge branch 'dev' of git://git.pcp.io/kenj/pcp into dev
Revert "linux pmda - nfs4 metrics"

This reverts commit 56281b7d3e56bd6b8fdfcb819bc08dea9b8fbde1.

Will apply alternate fix (which incorporates this, and more).
pmdalinux: nfsv4 operations metrics fix reworked

Reworks Kens earlier fix to deal with an NFSv4.1 operations
accounting indom problem.  This is slightly simpler and adds
in additional QA verifying the values returned for inst IDs
at the end of the array bounds as well, as well as the total
operations counter.