Combat Log - At Long Last

The combat log is finished, with formatting and colour support for
colour-coding character names and system messages (e.g.
"Paused"/"Unpaused").

Added some helper functions to the GUIManager to convert certain
datatypes:
int  =>  CEGUI::String
std::string  =>  CEGUI::String
col (RGB colour)  =>  hexadecimal colour (CEGUI::String of format
"AARRGGBB")