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

Fixes #344

Also updated the changelog with #377

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

Fixing when the path has space, it closes #368

Fix this by pointing to the tag via a git URL

Also update changelog and fix some linting errors.

Fixes #360

Adding 'rooms' API

fixes #364