In a previous change, ParsedFileDiff gained some new type-safe

attributes, leaving a handful of legacy attributes in its place. This

change updates the remaining code using these attributes. These were

primarily unit tests (as few diff parsers actually modify this object

directly, but rather than an info dictionary that's processed by the

main DiffParser). However, Git has more fine-grained control of its

parsing, so it needed to be updated to ensure it was setting the new

attributes using the right types.

Unit tests pass on Python 2.7 and 3.7 (with other in-progress changes).