MB-100: corrected lsof usage

We found that greping lsof output is not always working because lsof
cuts full process name and particularly godu processes were filtered
out.

New code is doing pgrep to find all relevant processes.

I've also fixed misc issue with finding sigar port process.

Change-Id: Ide7d0f3f98b46ed76be2168093f13dd738f68489
Reviewed-on: http://review.couchbase.org/30220
Reviewed-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>