PREVIEW_LMS_BASE must now be set (default value does not work for both edge and edx). Make this work locally as well.
https://edx.lighthouseapp.com/projects/102637/tickets/331

https://edx.lighthouseapp.com/projects/102637/tickets/331

Set the browser size on startup of acceptance tests.

Backbone notifications & font awesome integration

oh thank god this is finally getting merged

Use .get instead of [] to access env hash

Capture the exit code of the Mako template engine invocation on
asset preprocessing and abort from the Rake task on failure. This
will prevent the LMS from continuing its attempt to start up,
preventing further configuration errors.

If the `THEME_NAME` environment token isn't defined, then the
application.scss.mako file will crash during preprocessing. Use
.get to avoid a crash.

This reverts commit 90a9c386.

Because there are some cases where it's OK to fail, and it's not the user's fault

studio - revises z-index/element depth levels for modals, notifications, prompts, and alerts to use universal .depth Sass extends

This reverts commit e13556b8b6b54b2791fe7bb1ba2ae5cde10114ce. This is because the
JS files need to be loaded in a specific order for the tests to run properly, and
we don't yet have a way to declare that.

removed symbolset, replaced with fontawesome for gradable status; added transform-origin for saving notification animation to remove wobble

studio - changes all specific ss-icon-based selectors to use Font Awesome/generic icon- class name in notifications/prompts/alerts Sass

removed symbolset, replaced with fontawesome for alerts, notifications, and all references in js files

Also, a SystemFeedback model no longer has a `type`, it has an `intent`. This is
because SystemFeedback views have `type`, as well, and this prevents a naming
collision.

To reduce redundancy in tests

Doing so overrides the AJAX error popup

studio - removes the .is-fleeting class/animation that is handled by backbone's min/max time for notifications

studio - revises copy of server error notification to include a default message and removes associated actions from notifications