This removes the "update" button from the _config page, as well as removes the update functionality.
This adds the version detection code to _manager.
This is the first step to moving TheBrig Updating to its own page. The _manager page no can download the lang.inc from Github, and compare its value to the value currently held.
This change forces the version to be a floating number, so it can be compared, later.
This will allow this page to serve two purposes:
1. If a user wants to update from github, it will do so, and update the XML version information.
2. If a user has updated already and has the latest github version, but their XML is mis-matched.