gbp-clone: fix return value in case of GitRepositoryError

Signed-off-by: Markus Lehtonen <markus.lehtonen@linux.intel.com>
gbp-pull: fix --depth cmdline option

Signed-off-by: Markus Lehtonen <markus.lehtonen@linux.intel.com>
Add missing --git-

LP: #1112831
Fix typo

Thanks: Andreas Beckmann
Closes: #700443
examples: fix logging

Thanks: Carsten Schoenert
Document changes and release 0.6.0~git20121125