Feature/issue 165

Adds functionality that allows the user to whitelist certain potential trackers which need to be whitelisted to work. E.G. Youtube comments. This feature is already present in the chrome version but this would add it to the firefox version. CC @jsha for review. 
This is not an error case, simply a work around because for some reason my debugging console will only display messages of level error and not of level 'log'. I have changed it back to console.log. There is no other logging facility that I should be using.