Clean up common.py and PEPs 8, 203, 234, 257, and 263

Lint 9.07/10
Remove completed todo's
Remove deprecated StatusStrings().statusStrings
Use NumDict where appropriate
PEP 8: Optimize imports
PEP 8: Refactor variables that shadow built-in names
PEP 8: Refactor variables and arguments
PEP 8: Add and remove whitespace as necessary
PEP 203: Replace dict creation with dict literal
PEP 234: Use default iterators
PEP 257: Add missing docstring
PEP 263: Add encoding declaration