Refactor have_websocket_binary_frames().
Add tests for have_websocket_binary_frames().
Add Firefox 11 to have_websocket_binary_frames().
Test window.navigator.userAgent for truth instead of against null.

We're about to add a patch where it can be undefined rather than null.
See https://trac.torproject.org/projects/tor/ticket/9069#comment:8.
Move matches on ua to the block where ua is defined.

This bug was noticed by Arlo. I based the patch on
https://trac.torproject.org/projects/tor/attachment/ticket/9069/0001-Test-if-userAgent-is-a-string.patch.
Merge branch 'bug9069'

Conflicts:
	proxy/flashproxy.js
ChangeLog for #9069.
Post-hoc ChangeLog for the facilitator part of #9349.
Whitespace.
Change style a bit.