Match set metamodel for storing result snapshots

[bergmanngabor]

Title says it all

[bergmanngabor]

@abelhegedus here you go!

[abelhegedus]

The match set recording is partially integrated into the prototype of the testing framework.

The TestExecutor class already includes a method for turning matcher match sets into match set records, but it may be moved to a utility class since a developer extension to the Query Explorer will need it to save match sets into file (e.g. for aiding test case specification). Also, it will also probably become an API for clients to persist match sets from code.

Remaining issues:

• how to reference models that the match set is based on
• metamodel should be extended to indicate that a partial match was used for the matcher

[abelhegedus]

The snapshot storing and handling is ready.