RFC: Consider reintroducing the --license-reference option

[pombredanne]

After some good usage of the latest RC, we should IMHO consider reintroducing the --license-reference option and NOT always include this data in all scans. With --license-reference both rules and license reference would be included

[pombredanne]

In the worst case scenario if we match all the license texts and all rules, the reference will be 500MB in the JSON. This is creating a lot of boilerplate data!

We could add a --no-license-reference to turn this off for expert users.... but since the license detection and matches always include the URL to the matched license or rule, we should not make --license-reference the default.