Issuer dropdown

Use bootstrap dropdown for issuer.
Add "Manage Issuers & Gateways" link.
Fix ```ActionLink``` hooks in ```app.js``` to fire on state changes not just on page load.

Fixes #762.

![screen shot 2014-09-29 at 5 26 57 pm](https://cloud.githubusercontent.com/assets/3108007/4451660/683269d0-4839-11e4-8f97-b7fd0912b7c4.png)