This is a small feature release focusing on new extension management

capabilities.
Extensions can now be always-enabled (configurable via settings.py or

via an ExtensionManager subclass). These will be liste in the

extension manager, but can't be disabled.
Enabled-by-default extensions can now also be configured as attributes

on ExtensionManager.
There are also some improvements for extension dependencies and for

closing the confirmation dialog box when deleting integration

configurations.

Built the docs and read through them. Checked for build errors and

bad links.