Ember settings/general

- Settings fixture that doesn't seem to work
- SettingsGeneralRoute with model function calling api
- SettingsGeneralModel with save method stubbed
- SettingsGeneralController with actions for save, uploadLogo and uploadCover
- Let ApplicationRoute handleValidationErrors
- Fix actions hash in controller and use bind-attr
- Refactor to use single SettingsModel
- Implement description word count
- Fix broken ajax reference by actually importing ajax method
- Refactor to use count-words helper
- Refactor isDatedPermalinks into controller
- Refactor the isDatedPermalinks to use a custom setter
- Remove isDatedPermalinks code from the model
Merge pull request #2569 from jgable/ember-settingsGeneral

[Ember.js] Ember settings/general