Shorter user slugs (if possible)

Closes #4211
Abstracting away the deprecatedItems

Closes #4189

* moved `deprecatedItems` from within the function to the default config object
* addes tests
Merge pull request #4271 from felixrieseberg/iss4211-emailslug

Accept Invitation: Generate Slug from Name
Merge pull request #4269 from javorszky/iss4189

Abstracting away the deprecatedItems
Ignore Sublime Text project files
Merge pull request #4274 from netputer/ignore-subl

Ignore Sublime Text project files
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
Rename .object-list to .user-list

No issue
References todo comment in [users.scss](https://github.com/TryGhost/Ghost/blob/91c07e37bf5f6467ff65181581e8c7621033ab31/core/client/assets/sass/layouts/users.scss#L6-L7)

- Renames anything starting with `.object-list` to `.user-list`
- Adjusts tests to match
Merge pull request #4276 from PaulAdamDavis/object-list-users

Rename .object-list to .user-list
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