Changed settings dialog to an activity

This changes the settings dialog to an activity.
This removes [the issue with the outdated title bar](http://forum.xda-developers.com/showpost.php?p=55058754&postcount=11575) as well as a glitch in popup's white theme.

![settings](https://cloud.githubusercontent.com/assets/3890441/4076386/b4bd9818-2eb9-11e4-8fce-cb7308d1e77c.png)


There are quite a lot of lines changed but I divided the changes into multiple commits, thankfully it will be easier to follow them.