'gordon set' supports '+' prefix in arguments

Signed-off-by: Solomon Hykes <solomon@docker.com>
'gordon info': print basic information (including user name and email)

Signed-off-by: Solomon Hykes <solomon@docker.com>
Change the DB schema, upgrade version

* Store name and email of annotation's author
* Store full op name ("Signed-off-by" instead of "signoff")
* Small code cleanup along the way

Signed-off-by: Solomon Hykes <solomon@docker.com>
Remove unnecessary debug output

Signed-off-by: Solomon Hykes <solomon@docker.com>
Correctly handle individual commits and ranges in 'gordon signoff'

Signed-off-by: Solomon Hykes <solomon@docker.com>