TODO
====
o Prototype chaining length problem
o Parsing of TRUE and FALSE
o Help Package
o Load/Save Modal Dialog box
o Run selected command
o Zoom in/out
o Rework STOP and MEMBER and MEMBERP primitives
o Single Step and Status Panel
o Add Button LayoutManager
v0.7.0
x Integrate Lexer and remove Reader.
x Make OUTPUT and RETURN work
x Move Reader.transpose to evaluator
x BINOP and UNARY function precedences (minus!)
x Port some MSW functions that are simple to do
x Add Comments
x Add Logical/Boolean primitives
x Make forward delay optional
	x Add Turtle Speed selector
x Make turtle transparent?
x Revise Popup layouts
