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

- beginning methodinvoc typecheck
- bit of cleaning
- scan stdlib 3.0 now

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

- Test.py stop printing stars so much
- ClassInterNode - create common fields in constructor
- create super & contain set for Class & Interface

- added package name to hierarchy
- made sure hierarchy was appended correctly in recursion
- fixed Test.py to test single files, and to produce total result

- fixed getParseTreeNodes
- fixed getting name for TypeNode

- added CompEnv, which is a special enviornment for CompNode where it
also stores the imported stuff and the package name, so you can search
the globalEnv with those as well
- added type linking to ClassNode, where it checks the extends and
implements classes/interfaces and makes sure that they are real, and
stores them as the nodes in ClassNode

- can now successfully check that class has at least one constructor
- added rule fixing `this.x = 123;` in `J1_publicfields.java`
- cleaned up Test.py a bit more

- added AstBuilding.py
- new AstNodes.py that stores all Nodes and different types that we'll
create
- cleaned up Parsing.py heavily, now returns the parse tree
- cleaned up Test.py as best I could to accomodate everyone
- removed not needed file utils.py
- commented out my code in Weeding.py

- added new methodOrField thing that lets you invoc methods and fields
recursively infinitely
- statement can now declare and define any type
- removed arrayID nonterminal
- adjusted arrayAccess because of arrayID removal
- added a cmd in README to make my workflow more convenient
- commented out all the many many many prints in Test.py