Also retrieve tags for a cached git repo.

If someone refers to a tag in the revision field, git fetch might
not necessarily pulled that object.

As documented, the safe way is to run git fetch _and_
git fetch --tags
Merge pull request #39 from thorstenb/fix-git-fetch-tags

Also introduce some line-breaks to fix PEP8 errors.
add pep8 checking to GNUmakefile
Fix Debian build dependencies for python

Signed-off-by: Jan Blunck <jblunck@infradead.org>
Fix handling of symbolic links

Copy the symlink itself instead of its content.

Signed-off-by: Jan Blunck <jblunck@infradead.org>
Fix handling of symbolic links on cleanup

Lets simplify this and use shutil.rmtree() to replace our buggy implementation.

Signed-off-by: Jan Blunck <jblunck@infradead.org>
Honor submodules=disable as before (fixes #38)

Restore functionality of submodule handling after rewrite.

Signed-off-by: Jan Blunck <jblunck@infradead.org>