Don't call get_cmd if self.cmd is None. Standardize on <builtin> to describe use of the built in python.
Show not implemented message instead of raising NotImplementedError, warn if PythonLinter.check is not overridden.
Fixed python version resolution logic.
If the built in check raises an exception, print the traceback in debug mode.
Inline settings now must have a joiner and provide a value. This allows the matching to be much more efficient.
Fixed inline overrides when the option list is supposed to be a string.