Added ability to supply entry points directly. This is useful for
packages that don't declare their entry points.

No longer generate "py-" scripts implicitly.  Added a new option,
interpreter, to request such scripts and specifu their names.


git-svn-id: http://svn.zope.org/repos/main/zc.buildout/trunk@69991 62d5b8a3-27da-0310-9561-8e5933582275