Starting to add a browser action popup

Everything is done except the popup page itself
Added YouTube page to popup

Also refactored some constants to js\constants.js
Added Twitch page to popup

Also did some Twitch constant refactoring
Updated version number
Added Twitter page to popup

Also finished YouTube constant refactoring
Popup now won't open tabs that are already open
Address bar icon now shows when stream is online
Small implementation change of online indication