Allows hotkey handling of mousewheel events after minimap. Fixes#673.
Adds SendEvent to GUI objects, used in place of separate calls to
HandleMessage and ScriptEvent.
This was SVN commit r9340.
CGUI now represents a single 'page'. CGUIManager maintains multiple
pages and switches between them.
Split the XML files into pregame, loading, session and messagebox pages.
Added hotloading of GUI pages.
Minor GUI cleanups.
(Merge from hg 81862d33780c)
This was SVN commit r7214.