Merge branch 'jk/remote-helpers-in-python-3'

Prepare remote-helper test written in Python to be run with Python3.

* jk/remote-helpers-in-python-3:
  git_remote_helpers: remove GIT-PYTHON-VERSION upon "clean"
  git-remote-testpy: fix path hashing on Python 3
  git-remote-testpy: call print as a function
  git-remote-testpy: don't do unbuffered text I/O
  git-remote-testpy: hash bytes explicitly
  svn-fe: allow svnrdump_sim.py to run with Python 3
  git_remote_helpers: use 2to3 if building with Python 3
  git_remote_helpers: force rebuild if python version changes
  git_remote_helpers: fix input when running under Python 3
  git_remote_helpers: allow building with Python 3