Add set(index,value, author) to DataList
Decleanify
ChangeEquals matcher.
matcher for change lightly changed, added matcher for ChangeSet.
add matchers tests to test_all, use matchers in DataList.
DataList tests use matchers.
Refactor data_map_tests to use new matchers...
DataSet refactored + some other small changes.
Refactor set_stream_test
Data_sets tests refactored.
cleanify on adding
finished