Workaround for outlook, who doesn't like quoted-printable encoding

For example, outlook 2013 plus would not interpert the following html
(encoded via quoted-printable encoding):
<a href=3D=22http://engineering=
.como.com/ghost/signup/MTQxNTcwNzM5MTYwN3x5dXJ5QG5peC5jby5pbHx3NVBmUUN4RGZr=
cGhKc3FPOElybXNZNWtzR0FMTU9tRFI5UlNyRWQ4SGJZPQ=3D=3D/=22 style=3D=22color:
=

The workournd forces node-mailer to user base64, which outlook understands
well.
Faster dropdown animation for publish button

Closes #4390

- Apply same animation timing from the nav bar dropdown to the publish button dropdown
Cleanup User List styles

No issue

* Cleans up the Sass a bit
* Uses the same basic markup as other settings pages. Before, we had extra elements which required 'reseting'
Remove .eot & .ttf fonts

No issue

According to [caniuse](http://caniuse.com/#feat=woff), all the browsers we support (last 2 versions of major browsers) support the `.woff` font format. It's actually what pretty much all browsers will serve if its offered anyway.

This PR removes the .eot and .ttf font formats.

SVG remains as its the base file we use to add new icons & convert into other formats. It is not referenced anywhere.
Refactor component styles

Continues on from #4401

- Reformats the Sass to match our new style (property order, comments, & white space)
- Changes the modal container to a class from an ID (and adjust tests)
Merge pull request #4441 from PaulAdamDavis/cleanup-sass-components

Refactor component styles
Merge pull request #4433 from PaulAdamDavis/rm-ttf-eot-fonts

Remove .eot & .ttf fonts
Merge pull request #4391 from PaulAdamDavis/publish-transition

Faster dropdown animation for publish button
Merge pull request #4397 from PaulAdamDavis/cleanup-users

Cleanup User List styles
Enable .fade-out animations in Safari

Closes #4432

Random sidenote: Safari is a whiny non-animating wuss and figuring this
out took way longer than one would think.
Fix post tags input.

Closes #4378. Closes #4455.
- Trim whitespace from tag names on entry.
- Prevent duplicate tags in suggestion list.
- Fix unhandled exception that happens when backspace is pressed in
  an empty tags input box.
Merge pull request #4456 from felixrieseberg/iss4432

Enable .fade-out animations in Safari
Merge pull request #4457 from jaswilli/tags

Fix post tags input.
Update showdown to showdown-ghost 0.3.4

closes #2675

- update showdown to the newly published showdown-ghost module which has a fix for the lack of language support in codeblocks
Merge pull request #4458 from ErisDS/showdown-update

Update showdown to showdown-ghost 0.3.4
Fix gravatar request url.

Refs #4367
- 'http:' was accidentally left out when passing the gravatar
  URL into request, and request requires the full scheme to be present.
Merge pull request #4462 from jaswilli/gravatar

Fix gravatar request url.
Merge pull request #4349 from yurynix/master

Workaround for outlook, who doesn't like quoted-printable encoding
Add self to list of filtered users for editors

Closes #4412
Merge pull request #4463 from novaugust/dont-filter-self#4412

Add self to list of filtered users for editors