Optionally do not detect license when scanning a package

[pombredanne]

In order to support a lighweight and fast package-only scan I would like to have an option in the code (not a CLI option for now) such that we can bypass license detection when running a package scan. This is a nice to have have and would support nexB/scancode.io#720

[AyanSinhaMahapatra]

This is now there with #3689 both as an option in the code (see the API function get_package_data here which has the package_only option there) and as a CLI option: --package-only here. This is also there in scancode.io with nexB/scancode.io#1118. So closing!