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
render html in notifications

fixes #2844
Merge pull request #2854 from iBotPeaches/render_notifications

render html in notifications
Ember cleanup: double quotes + removed bad tag

- All HTML / Handlebars should use double quotes
- Removed a tag I meant to remove earlier
Ember cleanup: single quotes for JS

- All JS should use single quotes
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