Add extention point for CFG based optimizations
Merge remote-tracking branch 'upstream/master'
AST implementation of For
Small bug fix that confused me as I implemented sub expression elimination
Merge pull request #3 from drewying/ClassFixBranch

Small bug fix that confused me as I implemented sub expression eliminati...
Partial implementation of LValues
Associate symbol table with LValue for delayed lookup
Merge remote-tracking branch 'upstream/master'
added subexpression elimination and removed some unneeded fluff