Bug 1003998 - Bulk badge issuing

Note:  Also resolves 1046712 (Adds an "add comment" button to the issue page)

This adds support for bulk badge issuing to the badge admin page.  The "Email" field now reads "Emails (one per line)".  Users can enter multiple emails (and while it reads "one per line", it actually accepts white space, commas and semicolons as delimiters as well), and issue the badges all at once.

Important note: This requires [badgekit-api-client](https://github.com/mozilla/badgekit-api-client) v0.2.4, which does not actually exist yet.  It also relies on an update to [badgekit-api](https://github.com/mozilla/badgekit-api).  The following PRs need to be merged and deployed before this bad boy is loosed into the wild:

https://github.com/mozilla/badgekit-api/pull/127
https://github.com/mozilla/badgekit-api-client/pull/26