Create redmine.js

Add functional support for toggl button in Redmine
added redmine to readme
added redmine to manifest
added redmine to background
Tried to fix innerText errors
added redmine to styles

Style is specific to the default theme on redmine.org
added specificity for redmine selector

So the timer button doesn't show up on pages it's not supposed to
Merge pull request #54 from WatchSteveDrum/master

Added redmine integration