configure: allow use of python 3

# Note that if the Python conditional here evaluates True we will exit

# with status 1 which is a shell 'false' value.

if ! $python -c 'import sys; sys.exit(sys.version_info < (2,6) or sys.version_info >= (3,))'; then

  error_exit "Cannot use '$python', Python 2.6 or later is required." \

      "Note that Python 3 or later is not yet supported." \

if ! $python -c 'import sys; sys.exit(sys.version_info < (2,6))'; then

  error_exit "Cannot use '$python', Python 2 >= 2.6 or Python 3 is required." \

      "Use --python=/path/to/python to specify a supported Python."

fi