Added a completely new GUI, and a new doc file

    Important internal changes:
    * Most GUI callbacks are now methods of their HudSystems (cleans the code, mostly)
    * Saving/Loading has been disconnected from GUI for now, since we need to redesign how saving/loading works anyway.
    * CEGUIWindow now supports animations (which are used slightly)
    * A small change to microbe.lua, adding a species name. This is temporary, as the entire data-passing system needs to be changed (see #240)

    See #130