Extracted QualifiedNameFinder.getQualifiedName() from PyQualifiedNameOwner implementations
Made PyTargetExpression a PyQualifiedNameOwner
Fixed QualifiedNameFinder.getQualifiedName() for built-in names
Initial tests for types defined by mypy's typing module
Added nullity annotations
Refactored PyAnnotation into a PyTypedElement
Allow 'None' as a type defined by an annotation
Support for typing.Union type
Support for built-in collection types
Updated stubs to AST comments
Extracted resolve() for PyExpression
Support for 'typevar' generic types without inheritance
Extracted getUnionType() and getParameterizedType()
Missing newlines
Fixed searching for PyAnnotation stub if PyFunction is a stub
Tests of type unification for generic classes
Added heuristic: transform subscription expressions into operands in superclasses list

Subscription expressions in the superclasses list are most likely to
be used for parameterized classes, so we can just use the classes
themselves for resolving superclasses and creating stubs. It is needed
for parameterized classes in mypy.
Support for parameterized classes
Tests for typing.AnyStr
Support for function types