tools/python: Drop test.py

This file hasn't been touched since it was introduced in 2005 (c/s 0c6f36628)
and has a wildly obsolete shebang for Python 2.3.  Most importantly for us is
that it isn't Python 3 compatible.

Drop the file entirely.  Since the 2.3 days, automatic discovery of tests has
been included in standard functionality.  Rewrite the test rule to use
"$(PYTHON) -m unittest discover" which is equivelent.

Dropping test.py drops the only piece of ZPL-2.0 code in the tree.  Drop the
ancillary files, and adjust COPYING to match.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Wei Liu <wl@xen.org>
Reviewed-by: Lars Kurth <lars.kurth@citrix.com>

COPYING

@@ -57,7 +57,6 @@ Xen tree, retaining the original license, such as
   - Laurikari License
   - Public Domain
   - ZLIB License
-  - ZPL 2.0
 
 Significant code imports are highlighted in a README.source file
 in the directory into which the file or code snippet was imported.