Make TFL.Q_Exp compatible with Python 3.4

Python 3.4 changed the `__name__` of various functions in `operator`.

Add `M_Q_Root`, `normalized_op_name` to fix the doctest of `TFL.Q_Exp`.
Improve 3-compatibility of TFL.I18N
Simplify, and fix, `TTFL.SMTP.header` for Python-3