Closes #431 & #420: Profile icons in webmentions are now cached and served from the local server.
Refs #203
Closes #436: addMessage wrapper
Audio is now a default content type
Updates to Tags and Feedback form
Link to feedback form in the menu
Adding embedded mode
Fixing self-webmention issue
Further fixes to webmentions
Access control block margin
Thumbnails can now be forced square
User avatars are now forced square
Password inputs are always trimmed.

Fixes #440
Merge pull request #438 from mapkyca/error-messages

Closes #436: addMessage wrapper
Image transparency preservation on upload.
Improved profile edit screen

Now includes names and better avatar selection
Animated GIF support.
You can't upload empty audio posts.
Fixing opacity in Cherwell
Fixing date permalink in Cherwell footer
Switching to stars in Cherwell