957049 - Fixing 500 error from pressing enter

Pressing enter when focused on the rule input box caused the form to submit.
Now we're preventing that and instead binding enter to the add_rule link.
893596 - fixing repobinding to be specific to a single repo
Merge pull request #2336 from daviddavis/957049

957049 - Fixing 500 error from pressing enter
957049 - Fixing problems due to bubbling

Fixing problems with the solution I came up for in #2336. Namely, hitting enter
repeatedly created duplicates.
Merge pull request #2329 from jlsherrill/893596

893596 - fixing repobinding to be specific to a single repo
Merge pull request #2338 from daviddavis/temp_1369055854

957049 - Fixing problems due to bubbling