[DO NOT MERGE] Fix Bug #1032058 - Translation Form Alignment

Waiting on strings to be added to Verbatim. No reason we can't get the review started though.

1. Fix the expand and collapse widget so that the icons signalling functionality display.
2. Move the page meta information into its own expanding and collapsing area (the only meta information right now is tags).
3. Move the remaining information to fill the width of the page instead of being underneath the translation side.
4. Title this new section "version notes" (it's called version comments in the screenshot but I didn't like that).
5. Fix attachments so they show up again.
6. Document hierarchy fixes to support new organization.
7. Style fixes for page-button alignment.
8. Move Review Flags up in document order.

Potential site wide impact:
- changed behavior of clearfix() to clear using clear:both instead of :before
- removed wiki-block as extend for page-tags, page-attachments, page-comments and instead placed the class on the blocks.
We could use <code>margin-bottom: -(@margin-bottom)</code> to keep the two values in sync. It reads a little weird, but it tells Stylus to refer to the <em>last-used</em> value of <code>margin-bottom</code>.

Alternatively we could use a variable or even the <code>prevent-last-child-spacing</code> function from <i>mixins.styl</i>.