Multi parent policy compatibility

[Ramarti]

• Added compatibility checks for inherited multiple policies from multiple parents. We classify terms in these terms:
• Added contentRestriction UMLPolicy param
• Refactored UML licensing tests to use TestHelper, and added clarity on tests.
• To reduce complexity:
  -- Refactor IXXXParamVerifiers into IPolicyFramework
  -- Split linkToParent into different methods

Parameter	Multi parent eval	Reason
Attribution	Indifferent	Holder of all licenses must attribute the ones demanding it. Disputable
Transferable	Indifferent	Property of the license, not the IP
Commercial use	Equal or revert	One would infringe the other
Commercial attribution	Indifferent	Holder of all licenses must attribute the ones demanding it. Disputable
Commercializers	Indifferent	OK if verification checks for all licenses succeed
Commercial Rev Share	Indifferent	Licensing proccess must set all. Verifications must pass
Derivatives	Equal or revert	One would infringe the other
Derivatives Attribution	Indifferent	Holder of all licenses must attribute the ones demanding it. Disputable
Derivatives Approval	Indifferent	OK if verification checks for all licenses succeed
Derivatives Reciprocal	Equal or revert. If both true, policy must be equal	One would infringe the other
Derivatives Rev Share	Indifferent	Licensing proccess must set all. Verifications must pass
Territories	All equal, or some empty and the rest equal	All permissive is OK. Some permissive except some with same restrictions OK. Different restrictions is a conflict
Distribution Channels	Same as previous	Same as previous
Content Restrictions	Same as previous	Same as previous

[Ramarti]

Closes #43