Future Things to add:
	Maybe change global vars to be in a single BETH array.
	Let a single BETH interp work on multiple files (using a seperate
toplevel window for each one).
	Add graduated reading to exec commands
	Get all-interps to work on read-file.
	Provide a document (either standalone or part of the Help page) that
contains possible Unix/Wish commands that do useful things.
	Fix tab support (how?) Offer an indent mode (i.e. a tab gets replaced
with the number of spaces to align line with prev nonempty line.)

Possibilities:
	auto-saving (how?)
	Integrate menubar with frame widget (how?)
	Maybe C-z/M-z shouldn't move cursor.
	Break up long output lines in rmth.
	Switch Tab and Escape's functions, for Motif compliance.
	Emacs-like tags
	Provide a click-to-disappear option to labels that time out.
	When an exec filter (both input/output are used), put the input region
in the killbuffer.
	Integrate Beth with other Tk apps.
	Compatibility with other editors.
