#286 Add ability to exclude default build labels

[gtg3vv]

• New no-default-labels flag to avoid cache busting via build-date label
• Reordered default label so build-date is applied last

[gtg3vv]

Upon reviewing my tests, it looks like docker labels are sorted before being applied and the original request in the linked pr is not achievable. I don't think there is harm in leaving the line order as is, but I'm happy to remove that commit as well.

[mj520]

There are four very good options for no-default-labels flag

[tboerger]

As the current labels are deprecated I tend to drop them entirely and maybe add a flag to enable the replacement for the deprecated labels defined at https://github.com/opencontainers/image-spec/blob/master/annotations.md