OPENFLOW-1.1+.md: Update and correct OpenFlow 1.4 features.

Signed-off-by: Jean Tourrilhes <jt@hpl.hp.com>
Signed-off-by: Ben Pfaff <blp@nicira.com>
OPENFLOW-1.1+.md: Add OpenFlow 1.5 features.

Signed-off-by: Jean Tourrilhes <jt@hpl.hp.com>
Signed-off-by: Ben Pfaff <blp@nicira.com>