refreshless user logout

fixes #2842
- new Ember route for signout
- new API route to allow async signout
Full pass at inline API Docs

closes #2622, ref #2125
Merge pull request #2867 from ErisDS/api-docs

Full pass at inline API Docs
Merge pull request #2862 from morficus/master

refreshless user logout
Ember redirect to signup

closes #2779

- adds temporary code to redirect the ember admin to signup if a user doesn't exist.
- done serverside as this makes most sense?
Fix 12h cookie test issue.

fixes #2776
- Changed test to just check for 12h +/- 2500ms
Merge pull request #2870 from halfdan/2776-can-haz-cookie

Fix 12h cookie test issue
Removed holdover popover code in PostsPostController

Ref #2840
-Removed unused isEditingSettings and isViewingSaveTypes from PostsPostController
Update slug API to work with additional types

Closes #2866
-update slug API to handle users and apps in addition to
 posts and tags
-update existing tests
-add new functional tests for slug endpoint on http api
Enable post deletion from Ember admin

Closes #2849
-wire up delete post action in ember admin
-refactor ember modal dialog
-override RESTAdapter.deleteRecord to workaround Ember expecting
 an empty response body on DELETEs
Merge pull request #2869 from ErisDS/issue-2779

Ember redirect to signup
Merge pull request #2875 from novaugust/popover-cleanup

Removed unused popover code in PostsPostController
Merge pull request #2873 from jaswilli/2849-delete-posts

delete posts from post settings menu
Cache invalidation for post update

closes #2833
- Handle status change of post
Fix error when running Ghost with a socket

fixes #2879
- Syncronously unlink old socket file
Merge pull request #2877 from jaswilli/2866-slugs

Update slug API to work with additional types
Merge pull request #2876 from halfdan/2833-rasperize-cache

Cache invalidation for post update
Merge pull request #2880 from halfdan/2879-socket-issue

Fix error when running Ghost with a socket
Fix Editor/:postId 404 on draft

closes #2857
- in EditorRoute, get model from the datastore if it's there
- if page is refreshed, get model from `/posts` API with `{status: 'all'}`
Close post settings popover menu after delete post

No issue
-inject popover:service into modal component delete post
 controller so popover close can be triggered as part of
 the delete action
-remove unnecessary 'needs' from the delete post controller