Update to h2-16, hpack-10

Closes #1179

Note that there are no hpack tests for draft 10, yet. I left the test version at 9, since there is no implementation change.
This operation is literally called "Dynamic Table Size Update", so renamed the message.

http://tools.ietf.org/html/draft-ietf-httpbis-header-compression-10#section-6.3