TODO
====
o Integrate Lexer and remove Reader.
o Rework STOP and MEMBER and MEMBERP primitives
o Make OUTPUT and RETURN work
o Move Reader.transpose to evaluator
o BINOP and UNARY function precedences (minus!)
o Parsing of TRUE and FALSE
o Add Logical/Boolean primitives
o Single Step and Status Panel
o Load/Save Modal Dialog box
o Prototype chaining length problem
x Port some MSW functions that are simple to do
o Help Package
o Add Comments
o Add Button LayoutManager
o Run selected command
x Make forward delay optional
	x Add Turtle Speed selector
o Zoom in/out
x Make turtle transparent?
x Revise Popup layouts
