[WIP] Write mode polish

[xtine]

• Excerpt toggle label just says "Show"
  • remove show more/less text toggles
• Clean up nesting of comment attachment styles
  • line up "Upload Attachment" and "Save Response" buttons

Fixes: 18F/epa-notice#354

[cmc333333]

Something's wrong with my local setup, so I can't test locally yet. But! Changes look good in the abstract. Is this in a state to merge?

For future reference, most of the stylesheet changes are just moving things around. New stuff:

• .comment-context-toggle -> a.comment-context-toggle (with new text color)
• .comment-controls has a new nested class
• .comment-submission
• .comment-upload-button
• .comment-attachment margin, last-child
• .comment-submission

[xtine]

Multiple comment attachments are now stacked vertically and also accounts for extra long file names.

[donjo]

Just confirmed a few things with @jehlers:

• The actual cited text should stay black. The only part that needed to be gray (#767676) was what was in the gray bar.
• The bar should change from "Show" to "Hide" when it's expanded.

[xtine]

• Changed the cited text back to black, that's now on Write mode polish 18F/epa-notice#361
• Toggled text now Show/Hide
• Added "Delete response" back in.

[donjo]

Looks good. Is the bug in 18F/epa-notice#367 related to this in any way or is it ready to merge?

[cmc333333]

This works, but we should probably switch to a template at some point

[xtine]

The comment delete/save bug wasn't triggered with this PR.

[cmc333333]

General todo, we have lots and lots of e.preventDefault();'s now, which is concerning. I don't think we need to address that right now, however. Added #401 for this. I've not tested this locally, but if it looks good to you, go for the merge @donjo