build/tar/checkmodes - helper script to check file modes and ownership

Uses the Debian packaging recipe as a reference, and checks if the
local install has the same pcp:pcp and pcpqa:pcpqa ownership and
mode settings for files and directories.
qa/common - guess the name of gmake(1)

On FreeBSD, having to do MAKE=gmake check ... all the time is a
pain.  The real path to GNU make is hidden in builddefs, but not
used anywhere (before this change).
libpcp/logportmap.c - one additional diagnostic.

Helped deugging on FreeBSD, may be useful elsewhere.
libpcp/util.c - FreeBSD changes

1. cast to avoid compiler warning in alternate strchrnul()
2. new implementation of __pmProcessExists() for FreeBSD.
pmlogger_daily.sh - bizarre difference in find(1) semantics

The comment from the code should suffice!

    # FreeBSD semantics for find(1) -mtime +N are "rounded up to
    # the next full 24-hour period", compared to GNU/Linux semantics
    # "any fractional part is ignored".  So, these are almost always
    # off by one day in terms of the files selected.
    # For consistency, try to match the GNU/Linux semantics by using
    # one MORE day.
mysql PMDA - change metric semantics for "uptime"

The metrics mysql.status.uptime and
mysql.status.uptime_since_flush_status do count time, but their
most common use is as a value, rather than a rate converted metric.
Change the semantics from PM_SEM_COUNTER to PM_SEM_INSTANT.

This matches the semantics of other "uptime" metrics, like
kernel.all.uptime.

Thanks to Gareth Humphries at MessageMedia for pointing this out.
Merge branch 'dev' of git://git.performancecopilot.org/pcp/pcp into dev

Conflicts:
	src/libpcp/src/util.c

Choose Nathan's reimplmentation of strchrnul().
mysql pmda - update migrate.conf to track semantics change for uptime metrics
Rationalise golden output for some pmdasample tests
Updates to the online html documentation

Update all the URLs and slightly out-of-date procedures.
Add a placeholder for Markos quick reference guide which
will arrive shortly.
Python v3 updates in QA tests and monitor tools
Long option support added to pmdammv
Fix filter in qa/569 for highres event sample metric