ovs-ofctl: Add bundle support and unit testing.

ovs-ofctl: Add bundle support and unit testing.

All existing ovs-ofctl flow mod commands now take an optional
'--bundle' argument, which executes the flow mods as a single
transaction.  OpenFlow 1.4+ is implicitly assumed when '--bundle' is
specified.

ovs-ofctl 'add-flow' and 'add-flows' commands now accept flow
specifications that start with an optional 'add', 'modify', 'delete',
'modify_strict', or 'delete_strict' keyword, so that arbitrary flow
table modifications may be specified.  For backwards compatibility, a
missing keyword is treated as an 'add'.  With the new '--bundle'
option all the modifications are executed as a single transaction
using an OpenFlow 1.4 bundle.

OpenFlow 1.4 requires bundles to support at least flow and port mods.
This implementation does not yet support port mods in bundles.

Another restriction is that the atomic transactions are not yet
supported.

Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>