package/python-diskcache: new package

The package imports itself in setup.py to get the package-name and
version number. Dping this during the buildroot build would require
buisling host-python with sqlite support, which we are currently not set
up for. It also seems wasteful for just extracting the version number
and package name, so instead we replace the import by using a hardcoded
package-name and the version number stored in buildroot.

Signed-off-by: Marcus Hoffmann <buildroot@bubu1.eu>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

support/testing/tests/package/sample_python_diskcache.py

@@ -0,0 +1,9 @@
+from diskcache import Cache
+
+cache = Cache()
+
+cache['test'] = 123
+assert cache['test'] == 123
+del cache['test']
+assert 'test' not in cache
+cache.close()