Update the tests to work with oragono
Merge remote-tracking branch 'linkmauve/die-gc1.0-die'
And modify the tests to work, by adding the <x/> node in all join presences
Announce the urn:xmpp:sid:0 NS in MUC's disco#info
As required by XEP 0359
Should fix #3369
e2e: Implicitely include the handshake in all tests
Instead of having to write it manually everytime
Split all the e2e tests in their own files
Some duplication is avoided, but most importantly: it’s much much cleaner,
easier to find, functions have been cleaned up (functools.partial usages are
now hidden), etc.