Local Aliasing Tracking support

• Currently only parameters and local variables are correctly tracked
• method return values are treated as if they are newly created objects
  
  • working on typestate: objects should get the superset of typestate we analyzed for the called methods return values
  • working on alias: it should be checked if the returned values can be accessed from somewhere else (are aliased)
• field accesses are currently unsported
  
  • working on: this.field access should be possible soon
  • generally class.field accesses will not be allowed(checked) because they break encapsulation