closes#4368, fixes#1240 (spellcheck), fixes#4974 & fixes#4983 (caret positioning bugs)
- Drop CodeMirror in favour of a plain text area
- Use rangyinputs to handle selections cross-browser
- Create an API for interacting with the textarea
- Replace marker manager with a much simpler image manager
- Reimplement shortcuts, including some bug fixes
- see core/client/lib/assets-delivery/index.js for how this is done
- Turn off ember-cli fingerprinting
- ember-cli 0.2.0; Update .npmignore
- Fallback to old version of ember-cli-sass due to lib-sass errors
- Keep ember-data at beta-14.1 until we find the dep that's breaking on snapshot.attr
- Fix release task to ignore blank lines in .npmignore
- added grunt-bg-shell
- reorganized asset tasks into one location
- turn off ember-cli analytics
- remove app/config-dev and config-prod
- remove qunit from bower.json
- remove express from package.json
