ISSUE-139 proposal for today's telco

As mentioned earlier I would be fine with a hybrid approach for this issue.
Here's my draft idea to move forward with this issue

As Peter suggested we should have a single default implementation for all
supported contexts.
Users declare which contexts their components supports and provide a single
implementation for all those contexts. whenever a component is used in a
wrong context, the SHACL engine will return violations for all focus nodes.
SHACL engines may additionally use the context information for UI building
or suggesting optimizations in the shapes graph.

Users may override the default implementation based on a simple filtering
mechanism (as described in this mail
https://lists.w3.org/Archives/Public/public-data-shapes-wg/2016Jun/0033.html
).
A SHACL engine will try to see if any overridden implementation applies for
the current instance or use the default as fallback

Best,
Dimitris

-- 
Dimitris Kontokostas
Department of Computer Science, University of Leipzig & DBpedia Association
Projects: http://dbpedia.org, http://rdfunit.aksw.org,
http://aligned-project.eu
Homepage: http://aksw.org/DimitrisKontokostas
Research Group: AKSW/KILT http://aksw.org/Groups/KILT