Extend mapped concept metamodel to include multiple inputs
- Multiple source element ids
- Each with assigned grammars and functions
(from redmine: issue id 537, created on 2018-01-22tgradl, closed on 2018-01-22)
- Relations:
- relates #536 (closed)
(from redmine: issue id 537, created on 2018-01-22tgradl, closed on 2018-01-22)