Administration backend

[MengelCode]

If the game does run on a webserver, the server owner should have possibilities to modify the game a bit without coding on their own. This could go from modifying game mechanics (items, enemies) to disabling / enabling features (#125 when that will come) to writing the name of the server administrator or something like this.

This will most likely be based either on PHP or Python. But of course, if those environments are not available (you directly open the index.html), the game should work just as is.

[MengelCode]

#137 will be held back by that.