Export backup prior to migration

Closes #847
- Added logic to export database to the `core\server\data\` folder prior
to beginning a migration.
- Factored out versioning logic from migration to prevent circular
references
Merge pull request #2841 from gotdibbs/847

Export backup prior to migration
Move jshint logic out of Gruntfile.js and into .jshintrc files
Ember: correcting code style
Merge pull request #2864 from lholmquist/jshint_separate

Move jshint logic out of Gruntfile.js and into .jshintrc files
Ember: jshint single quotes

- also remove .jshintrc from releases
refreshless user logout

fixes #2842
- new Ember route for signout
- new API route to allow async signout
Mail API fixes

- The mail API endpoints weren't quite working correctly. Now working but still need love
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