* ansible: use unicode_literals everywhere since it only needs to be
compatible back to 2.6.
* compat/collections.py: delete this entirely and rip out the parts of
functools that require it.
* Introduce serializable Kwargs dict subclass that translates keys to
Unicode on instantiation.
* enable_debug_logging() must set _v/_vv globals.
* cStringIO does not exist in 3.x.
* Treat IOLogger and LogForwarder input as latin-1.
* Avoid ResourceWarnings in first stage by explicitly closing fps.
* Fix preamble_size.py syntax errors.
Although these are synonyms in Python 2.x, when using MyPy to typecheck
code use of file() causes spurious errors.
This commit also serves as one small step to Python 3.x compatibility,
since 3.x removes the file() builtin.
David Wilson