New helper object to controll dump file processing

* New class DumpProcessingController
* Updated existing examples to ue this class
* Extended test cases
Update release notes
Removed method to process recent dumps from WmfDumpFileManager

This is now covered by DumpProcessingController.
Mention breaking change in releae notes
Merge remote-tracking branch 'origin/master' into dump-processing-pipeline
Adopted example code to use new processing controller

(and fixed processing of property documents, which was missing)
Merge pull request #66 from Wikidata/dump-processing-pipeline

New helper object to control dump file processing