Experimental start to the tel discovery/verification
Only unregister if new route is different
Fix clear-before-continue and allow pre-registered users to click a "finish" button
Clear old route before setting new one

Closes #47
When submit no route, delete existing route

Closes #48
Pass through IQ to DM route

At least, for IQ that we don't handle here in Cheogram.

Closes #45
Send delivery receipts

If upstream gateway doesn't generate them, then the best we can do is
generate them ourselves.

Closes #24
Need this version for TQueue
We need this version
Merge upstream caps into our caps

And also into our disco info.

Closes #44
Pass through presence at all
Send presence when subscribed
Hack to pass through some kind of error at least
Save if already registered to gateway
Show currently-set route if there is one
Show pre-registered form when gateway gives us one
Pass proxied stanzas from 1:1 route back through
Pass errors through better during 1:1 setup
Route direct messages if route exists
Proxy through the registration form and record the route