*Moved RValue and Line into separate files
*Moved static members of Assembler into new static class Assembly which is used by RValue and Line
+Assembly class: contains static members related to 6502 assembly in general
+AssemblerGroup: Grouping of Assembler objects so that they can share labels and global variables
*GUI demos two assembly sources but no place to put global vars yet
*Text inputs monospaced
*Assembly class methods split into more methods, such as so that FirstPass can be called on multiple Assembler objects and then Assemble called on them