tools/glusterfind: add query command to list files

tools/glusterfind: add query command to list files

When session information is maintained outside Gluster, there needs to
be some mechanism to list files starting from a time-stamp. This patch
implements the feature via the "query" command-line option.

The only caveat is that the first time the query command is run for the
volume, it will likely report that "historical changelogs are not
available". This is due to the fact that changelogs had not been turned
on for the volume so far. So the volume options need to be turned on
outside glusterfind or the since_time need to be greater than the
current time when the query command is run for the very first time for
the volume. The query command turns on the required volume options for
collecting changelogs.

Change-Id: I6cb7a57a5ecd166210e2eb4deede06d40ccfa996
BUG: 1272006
Signed-off-by: Milind Changire <mchangir@redhat.com>
Reviewed-on: http://review.gluster.org/12362
Tested-by: NetBSD Build System <jenkins@build.gluster.org>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Aravinda VK <avishwan@redhat.com>