Re #9199. A bit of refactoring of MultiDomainFunction and M-D-Creator.
Re #9199. Implement iterationStarting() method on M-D-Function
Re #9199. MultiDomainCreator creates output workspace
Re #9199. Added a unit test
Re #9199. Added another unit test
Re #9199. Fixing the builds.
Re #9199. Changes in MDEvents
Re #9199. Fixing compiler warnings
Re #9199. Testing that setWorkspace is called.
Re #9199. Changed names of the output workspaces
Merge remote-tracking branch 'origin/feature/9199_multidomain_improvements'