Remove <Unknown> entry from Authentication Status box.

Remove <Unknown> entry from Authentication Status box, these entries were for keypairs(AuthKeyPairAmazon), and had null in authtype field in the table.

https://bugzilla.redhat.com/show_bug.cgi?id=1158180
https://bugzilla.redhat.com/show_bug.cgi?id=1158179
Merge pull request #1218 from h-kataria/remove_unknown_credentials_from_cloud_summary

Remove <Unknown> entry from Authentication Status box.
Angular Prototype for Repository Editor

- Added a controller specific to the repository editor form
- Added a directive specific to the repository editor form
- Added a couple generic directives that would have an application-wide usage
- Changes made to RepositoryController (@edit related changes)
- Added a JS function to display flash messages triggered through Angular events
- Added Jasmine tests

#1064