cufo: Formatted Output

Modules
	cufo/attr.h: Markup Attributes
	cufo/attrdefs.h: Various Attribute Definitions
	cufo/fwd.h: Forward Declarations
	cufo/dsink.h: Data Sinks with Markup Handlers
	cufo/stream.h: Formatted Ouput Streams
	cufo/tag.h: Tags for Light-Weight Markup
	cufo/tagdefs.h: Various Tag Definitions
	cufo/termstyle.h: Terminal Style Specification
	cufo/textsink.h: Text Target Styler and Stream