Test in progress
Fixed errorneous behaviour on files removing.

Fixed errorneous behaviour on files removing during uninstall procedure.
Because this bug, installation become corrupted during uninstallation
python based schemas, because they removed bin/python and some other
files, installed by virtualenv.

Also, this fix includes a unittest refactoring. Now each test runs in
it's own temp directory and is able to instantiate schema, using it's
class name.