Improve padding on #home page

Been bugging me for some time...
Improve the logging emailer used for testing

Stop overriding functions in the DummyMailer class so that there is
full support for all the mailer functions. Logging is acheived by a
small list subclass that thunks the list append method to log.
Re-order some imports
I broke the padding on the account forms
Remove unused displayer.coffee
Remove hover state on tabs

Reverts 3540eab.
Improve annotation typography

 * Move the styled-text module into it's own file.
 * Add markdown examples to the pattern primer.
 * Fix list item, blockquote and code styles.
 * Improve font sizing of heading elements.
 * Ensure code, serif and sans-serif are rendered at similar sizes.
 * Style sub lists.
Ensure styled-text is applied to all markdown docs
Fix styles of the home/help/auth pages

We now use the styled text module here and overwrite it to work with
larger copy.
Move textarea styling into form module
Fix Searchfilter's bad handling of quote characters

We're parsing the search expression for " and ' characters
to treat the text between the quotes as one unit.
But this wasn't working well, when there was a facet before the quoted part,
the quote characters were leaking into the search as meaningful characters.

I.e. tag:"no way" , the system was looking for '"no way"', instead of just 'no way'.
This has been fixed

With this proper working tag-search,
when the tag has space characters, is just adding two extra quotes.

Fix #1431
Remove display: run-in from thread indicators

This is broken in Safari and removing it doesn't appear to affect the
rendering in any of the other browsers.
Small fixes to tab styles

* Same padding to top/bottom of tags.
* Remove unused styles.
* Apply consistent padding/margins and remove extra margin above
  first line of tags.
* Update pattern library.
All sheet tabs now have a bottom border
Fix responsive styles when running Sass >= 3.4

In Sass 3.4 the index() function now returns null instead of false. So
we just perform a truthy check in the respond-to mixin rather than a
direct comparison.

http://sass-lang.com/documentation/file.SASS_CHANGELOG.html
Merge pull request #1446 from hypothesis/fix-sass-3-4

Fix responsive styles when running Sass >= 3.4.
I broke the padding on the account forms
Tagging v0.3.1
Update CHANGES
Fight the proliferation of csrf nonsense

I had tried to remove it, thinking the `csrf` one wasn't used because
`identity` used `csrf_token` but unfortunately the `session` module
still used `csrf` and deleted it from the model during the response
transform. Instead, let the `csrf` value stick to the model to be
available on session object and mark the `csrf_token` value as the
deprecated one in the backend. Support for that will drop further in
the future.