A number of changes to the toplevel make file and dir structure.
- deb-src and deb-release fail because debian was a symlink. This is not allowed
so instead we git clone and then move the debian dir to the toplevel.
- Fix the clean target to only run rules/debian if the debian dir exists.
- Drop probert as a submodule and instead clone it as needed, controlling the
version through a Makefile variable.
Signed-off-by: Ryan Harper <ryan.harper@canonical.com>