Update to VCHAN 1.0.0 FLOW signature

We need to add a line-oriented buffered parser to interface to the
buffer-oriented FLOW interface.

Signed-off-by: David Scott <dave.scott@citrix.com>
Regenerate OASIS

Signed-off-by: David Scott <dave.scott@citrix.com>
Merge pull request #1 from djs55/use-FLOW

Use FLOW interface