Get rid of traceLog() entirely

[praiskup]

It’s probably a matter of perspective, but it doesn’t really help with debugging—quite the contrary. It has only ever complicated my real-world debugging of Mock by adding an unnecessarily large call stack (try working with pdb and Mock, and you quickly learn that you can’t live without MOCK_TRACE_LOG=false, which was implemented as a result of my long-term despair).

There is also issue #1666, which seems to indicate that this may even slow down Mock execution.