Add input for local instance

[golfinq]

Add a checkbox toggle and input box to the front end to allow the user to automatically change all the links on the "communities" tab to be within their instance.

-Edit- Addresses: #31, #40; the implementation here is a relatively simple way to address these issues

[tgxn]

This looks okay, There's definitely some performance issues when typing in the box. but it'll do till I get time to work on #5