Code cleanup.

First pass at implementing @aron's mockups.

Fix bugs, breakout markdown into its own directive

Forgot to add markdown.coffee

Search for usernames

Remove d3 dependency

Replace the background with a grey bar using a div.

Previously it would update on every scroll or resize event fired on
either the document or body.

This improves performance while scrolling as we're no longer destroying
and recreating every tab on each call to update.

This makes the style and attribute iterators work correctly

Cleanup font icons and add Markdown glyphs

We now only have one of each icon type where possible.

As now we only use it with a false parameter every time,
it is no longer serving any purpose

This way we can search both for the username and the full user format.

Fix #1456

Sync the bridge after beforeAnnotationCreated

Spotted by @gergely-ujvari

This ensures that plugins on both sides have fired and any resulting
modifications are synchronized (document plugin, for instance).

Fix #1502

Remove parent and url values in streamer and notifications

Conflicts:
	h/static/styles/app.scss

Change save shortcut to meta/ctrl + enter.

Classes had been added to the stylesheet but not to the template, and
those that were had typos.

This was causing the annotation to render with too much whitespace now
that it uses sections rather than divs.

Hyphenate camel case filenames