just creates or updates the "projectname.egg-info" directory, without
building an egg.  It's used by the ``bdist_egg`` command now, and will be
used by the ``test`` and ``develop`` commands later on.

--HG--
branch : setuptools
extra : convert_revision : svn%3A6015fed2-1504-0410-9fe1-9d1591cc4771/sandbox/trunk/setuptools%4041077