Made some modifications to the code contributed by @thierrytiti and documented
the change.

Fixes #344

Also updated the changelog with #377

Conflicts:
	dev.html

Issue #370 registration fails

Support to send the registration form as legacy or xform, we
use the same variable form_type that was already being used when
calling render
Added submission tests

Two tests were created to see if RegisterPanel.form_type is set
to correctly to legacy or xform when receiving server registration
form.

Fix collapsed group visibility on reload

Close #374

Fixes #372

Fix rooms grouping examples in docs

Conflicts:
	converse.js

Fixing when the path has space, it closes #368

* Unsubscribing
* Incoming subscription requests.

Noticed that it's not necessary to call "unauthorize" when setting
subscription="remove".

Did a bit of renaming and fixed a bug in updateContact where a user wasn't
created when it should have been.