allow DRAW"u" etc without length spec"
document DRAW syntax: length spec in U[n] etc
DRAW: allow TA, A, and C commands without number specified, but only if followed by a semicolon.
HELP on DRAW: document behaviour of not-quite-optional n in TAn, An, Cn.
pcjr: use 4x3 aspect ratio, not the Tandy value. Matches with MESS and test programs.
DRAW: adjust for aspect ratio when drawing with A or TA angle set
fix crash on PAINT bg pattern not the same length as fg pattern
don't break tile fill on empty background for patterns with empty lines
fix missing brackets that led to optional SOUND parameters not being treated as optional