Created a global import function for each .s file and called before test(). Fixed a custom test case

Fixed some minor issues with arrays. Can't test yet. Need to wait till merging name node changes and fixing .length

fixed codeGen to work on multiple classes. fixed small bug for reachability check. fixed bug on codeGen util functions. Cleaned up code in classNode

- change Test.py to run reachabilityChecking
- basic ASTNode reachCheck
- implemented reachability in: MethodNode, IfNode, WhileNode, ReturnNode
- tiny bit of cleanup (whitespace)

- show elapsed time in Test.py
- GlobalEnv no more '.' in front of types without a package
- lots of GlobalEnv:getNode fixes
- fixing but still testing GlobalEnv:weedGlobalEnv
- cleaned up some comments

- added fieldType to FieldNode
- added myType to NameNode
- fixed NameNode:checkStatic
- recursively calling disambigName exactly the same as how we do
checkType
- starting NameNode:checkType
- cleaned up Test.py commented code

Added code for Name disambiguation. Fixed CFG for field access. Moved test cases to the correct directory. Not tested yet