Minor update to traceback stub
Minor update to logging stub
Add skeleton calendar stub
Add test cases for invalid number of type args
Fix bugs in ast traverser
Rename test case
Check type variable counts in a new analysis pass

This helps the implementation of more reliable binding of Generic,
typevar, etc.
Refactor type variable analysis
Fixes to several test cases
Fix semantic analysis of Generic etc.

Detect if Generic has not been imported and also handle qualified
references to Generic.
Add semantic analyzer test cases
Detect duplicate (Abstract)Generic
Support qualified references to typevar(...)
Add semantic analyzer test case
Reject invalid metaclass name
Add parser test case
Add and update semantic analyzer test cases
Verify that metaclass is a class
Check arguments to typevar()
Fix local type variable definitions