add google:queue spec

This is purely because http://dave.cridland.net/xeps/google-queue.html
is down, and I need to be able to link people to the spec.
Once Dave has added it to the Historical XMPP spec archive, this will
be redundant, so don't merge this commit into master.
Add initial FB queue tests

Currently using https://bugs.freedesktop.org/show_bug.cgi?id=38943
as a reference for the protocol.

The decision to switch focus to fb suspend is because it:
a) Fits the BOSH Pause model more closely (for easier code cribbing)
b) Fits the iOS wakeup limit better (push notifications are the
   recommended mechanism for incoming messages on iOS)
Sleep and wake 100 times before running test

This test should make it easy to spot any leaked
FSM processes in the server. I suspect that there
will be many.
Add suspended_timeout test

This adds a "pause" xml attribute that should work a bit like
<body pause="60"/> from http://xmpp.org/extensions/xep-0124.html#inactive

Note that this test in its current form SHOULD fail around WakeResult2
because we have paused for twice as long as we requested. Once I have this
implemented in the server, I will amend this commit.