GUI: Graphical code

Curses and Window code.

File	Description
gui/color.c	Color and attribute parsing
gui/curs_lib.c	GUI miscellaneous curses (window drawing) routines
gui/dialog.c	Dialog Windows
gui/mutt_curses.c	Wrapper functions around Curses/Slang
gui/mutt_window.c	Window management
gui/reflow.c	Window reflowing
gui/terminal.c	Set the terminal title/icon