Update Ember to 1.8.0.

Closes #4316
- Ember@1.8.0.
- Ember-Data@1.0.0-beta.11.
- Change templates to use new Ember.Select syntax and other minor
  cleanup.
- Adjust functional tests.
File structure cleanup
Var cleanup
Better comments

Also introduces a new format of file opening comment, to outline what happens and a contents list.
Merge pull request #4342 from PaulAdamDavis/sass-cleanup

Cleanup modules Sass
Merge pull request #4361 from jaswilli/ember18

Update Ember to 1.8.0.
Handle null/undefined value in test assertion.

No Issue.
- Test is not guaranteed to get a setting that has a "value"
  so we need to handle the case where it's null or undefined.
Merge pull request #4363 from jaswilli/fix-test

Handle null/undefined value in test assertion.