
Moved the body of bin/swift-form-signature into swift/cli/form_signature.py, like was done with swift-ring-builder and others. Added a couple basic tests; there's not 100% coverage, but it's better than the 0% coverage we had before. It's almost a straight forklift, but I changed exit() calls to return statements. Change-Id: Ie2f702c070da24d9cdface83b9e838e9e2965085