Report separately unknown licenses and related non-conclusive license detections

[pombredanne]

Short Description

Several rules are used to detect license reported as "unknown","unknown-license-reference", etc. are mixed with bona fide conclusive license detection rules that point to concrete licenses.
We should split these and deal with them and report them separately (See also #1675 )
The benefit would be clearer separation of actionable license detection results vs. detections that would need some review.

Select Category

• Enhancement
• Add License/Copyright
• Scan Feature
• Packaging
• Documentation
• Expand Support
• Other