	Cursor Motion

Use the schema:

	putpad(tgoto(CM, col, line));

Cursor codes understood by tgoto:

%d	as in printf, 0 origin
%2	like %2d
%3	like %3d
%.	like %c
%+x	adds x to value, then %.
%>xy	if value > x adds y, no output.
%r	reverses order of line and column, no output
%i	increments line/column (for 1 origin)
%%	gives a single %
%n	exclusive or row and column with 0140 (DM2500)
%B	BCD (16*(x/10)) + (x%10), no output.
%D	Reverse coding (x-2*(x%16)), no output.
		(Delta Data).
	
	Example cm strings

:cm=^T%.%.:		Microterm Act IV
			Ctrl T, straight binary row, column.
:cm=\E=%+ %+ :		ADM-3A
			Escape, =, binary starting with space.
:cm=6\E&%r%2c%2Y:	HP 2645
			Pad 6 ms, escape, &, two digit column,
			c, two digit row, Y.
:cm=^T%+^X%> 0%+P:	Microterm Mime
			Ctrl T, binary row starting with ctrl X,
			binary column ranging from P thru DEL
			and then ! through O, avoiding low
			control chars and ^D/^I/^J/^@ lossage.

