Set SERVER_EMAIL so that mail_admins works

Disable SSL cert validation for Zendesk API

studio - alerts: synced up styles and sample markup

They are currently using a CA that is not installed on our servers. Since it
isn't a top-tier CA and we aren't submitting anything particularly sensitive
anyway, we don't have to feel too bad about this.

studio - alerts: synced up example HTML to show advanced settings live notification, aria roles, and action classes; integrated typography mixins

Pass through the value (either default or inherited) that a metadata field WILL have if it is not explicitly set.

Hide the Comments Service API key during logging.

Added unit tests for safe_key() to resolve bug 392.

Vik/fix/oe bugs

kludged in the note tab panel so it can be turned on and off using the policy editor by adding "notes" to "advanced_modules."

Delete two lines.  without this, the xblock fields are never created in cases where the module is "fresh" (ie has no existing data)

Feature/giulio/accessibility

these are configured to be too long in the settings.

made signup form labels and close modal button accessible friendly and tweaked login form to match signup form

Pass additional field information from editable_metadata_fields, remove system_metadata_fields variable.

Ignore the js files that are compiled from coffeescript when running the...