touch: shorten touch's docstring to make it fit into a one line This make it show completely (untruncated) in `hg help -e evolve`. This follows up on fed946edc293 where the docstring got unwrap for that purpose and thus made the line length exceed 80 columns.

# name space package to host third party extensions
from __future__ import absolute_import
import pkgutil
__path__ = pkgutil.extend_path(__path__, __name__)