devel/py-zc.lockfile: Add py-zc.lockfile 3.0.post1

The zc.lockfile package provides a basic portable implementation of interprocess
locks using lock files. The purpose if not specifically to lock files, but to
simply provide locks with an implementation based on file-locking primitives. Of
course, these locks could be used to mediate access to other files. For example,
the ZODB file storage implementation uses file locks to mediate access to
file-storage database files. The database files and lock file files are separate
files.