ofproto: Break out perl code for sorting multiline messages

The flow monitoring tests includes a perl script to sort multiline
messages.  This commit breaks it out of an individual test so that it can
be used elsewhere.

Signed-off-by: Simon Horman <horms@verge.net.au>
[blp@nicira.com changed approach from a separate file to a shell function]
Signed-off-by: Ben Pfaff <blp@nicira.com>
ofproto: Honour NXFMF_OWN flag of flow monitors

If NXFMF_OWN is set then full updates should be sent.
Prior to this change an abbreviated update is always sent
to the controller to which a monitor belongs, that is,
the NXFMF_OWN flag is ignored.

Also:
* Update existing flow tests for this chagne
* Add a test to exercise NX flow monitor with !own

I noticed this while working on support for OpenFlow1.4 flow monitors.

Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Ben Pfaff <blp@nicira.com>