o Run unit tests under both python2/3
o Import misc into cpppo namespace, and move reprargs, logresult decorator
  and lazystr log helper into misc.
o Correct unit tests for move of raw input collection into '_input'
o Update 'natural' sort key function to work with heterogenous lists
  under python3, where comparing incomparable types raises Exception
o Increase "echo" test drain delay, for success at higher logging levels
o Allow tnetstrings_test.py to load tnetstrings.py, even if run from
  a different directory, by adding __file__ dir to sys.path.