Shorter user slugs (if possible)

Closes #4211
Autosave Draft posts

Ref #1413
- If the user stops typing for 5 seconds, a "typingPause" action is sent from the GhCodemirrorComponent
- Editor-base-controller ties the "typingPause" action to its "autosave"
- If a post is being saved and does not have a title, the title is set to "(Untitled)"
- Cleanup editor base controller property dependencies and code
Change autolinked URLs to output nice quotes

ref #4257

- This is a follow on from #4257 where I updated the codestyle.
- We were outputting escaped single quotes when double quotes would be much nicer.
- Changes the HTML output from our markdown conversion (non-breaking change)
- Updated tests to match the new output
Use DS.Model#eachAttribute in editor-base-controller

Closes #4279
Merge pull request #4281 from novaugust/iss4279

Use DS.Model#eachAttribute in editor-base-controller
Refactor helpers & tests into individual files

no issue

- Split theme helpers into individual files for each
- Do the same for tests
- Have utils to share some things between them
- Move assetHash onto config
Merge pull request #4283 from ErisDS/split-helpers

Refactor helpers & tests into individual files
Fix up labels for controls in post settings menu

No issue
Merge pull request #4288 from jaswilli/psm-labels

Fix up labels for controls in post settings menu
Merge pull request #4220 from felixrieseberg/iss4211

Shorter user slugs (if possible)
Show all invited users and infinite scroll active

Closes #4239
Update to use libsass 3.0

No issue

This doesn't give us any advantages at the moment, but is less buggy (in edge cases) and ;gets us be more awesome in the future.

Look at https://github.com/sass/libsass/releases/tag/3.0 to see what's in Libsass 3.0
Merge pull request #4296 from PaulAdamDavis/update-libsass

Update to use libsass 3.0
Merge pull request #4289 from jaswilli/issue-4239

Show all invited users and infinite scroll active
Speed up user menu animations

No issue

- Speeds up the animation duration when the user menu opens
- Effectively removes the user menu closing animation
Remove console.error from shortcuts-route mixing

No issue

Safari (iOS 8 & OS X Yosemite) throws a massive hissy fit about `console.error` and goes on to break all the things.
This PR simply removes it.
Fix alignment on burger menu button
Remove hover transition inside dropdowns

No issue

- Removes the transition on hover/focus states for items/links in dropdowns
Merge pull request #4298 from PaulAdamDavis/speedier-user-menu-animations

Speed up user menu animations
Remove shadow from right of tag bar

No issue

- Completely removes the shadow from the right side of the tag bar