Changed booleanLit and Nil nodes to implement singleton patterns
Merge branch 'vbranch' of https://github.com/tford9/CSC-4101-Projects into vbranch
Merge branch 'master' of https://github.com/tford9/CSC-4101-Projects into vbranch

Conflicts:
	proj1/Project_Skeleton_Code/BooleanLit.java
	proj1/Project_Skeleton_Code/Nil.java
Updates to parser and scanner - towards handling cons nodes and lookahead
Updates to parser