porting: various fixes regression tests OSX/FreeBSD

- `wc -l` on OSX/FreeBSD adds spurious spaces, this clobbers
  up TAP output parsers - fix it.
- `umount -l` doesn't exist on OSX/FreeBSD use 'umount -f' if
   available.
- Add check for 'file' version, to handle mime type variations
  across versions
- Converge 'glusterfs --attribute-timeout=0 --entry-timeout=0'
  into '$GFS'
- Modify remaining 'mount -t nfs' to use 'mount_nfs'
- Update sha1sum for OSX to use 'openssl sha1'.

Change-Id: Id1012faa5d67a921513d220e7fa9cebafe830d34
BUG: 1131713
Signed-off-by: Harshavardhana <harsha@harshavardhana.net>
Reviewed-on: http://review.gluster.org/8501
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Kaleb KEITHLEY <kkeithle@redhat.com>