created a UnstructuredGridToUnstructuredGridFilter and a test for it
removed the GenerateData() method
added some methods to the filter for multiple inputs
added a new test for the multiple inputs and outputs
had to add a graft method for mitkUnstructuredGrid
Merge branch 'bug-18511-UnstructuredGridToUnstructuredGridFilter' into bug-18511-UnstructuredGridToUnstructuredGridFilter-IntegrationBranch
Merge branch 'bug-18511-UnstructuredGridToUnstructuredGridFilter-IntegrationBranch'