Add max_terminal check for UniqueTermManager, with unit test cases
Add max_terminal check for UniqueTermManager, with unit test cases

Implemented by refactoring UniqueTermManager as a subclass of
NamedTermManager, but with uniquely generated names

Revert to previous version of management.py

takluyver/terminado,ellisonbg/terminado,akalipetis/terminado,ResearchComputing/terminado,ResearchComputing/terminado,ellisonbg/terminado,akalipetis/terminado,akalipetis/terminado,takluyver/terminado,ResearchComputing/terminado,ellisonbg/terminado