[cbcollect_info] added "path to initargs" flag

So that we can do cbcollect_info for cluster_run nodes

Change-Id: I0705f8805f23352eb255474036f06d4cbcbe7b76
Reviewed-on: http://review.couchbase.org/37285
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Reviewed-by: Artem Stemkovski <artem@couchbase.com>