store the expired repos.

dropped by accident earlier.
Support skipping the depsolve stage.
Add iterables splitting function.
Create a YumHistory wrapper.
refactor: Extract transaction IDs/offsets conversion to a standalone method.
Support querying the last transaction ID in the history.
Generalize the PackageMatcher to an ObjectMatcher.
Add iterators exhaustion testing function.
Fix TypeError raised when Base.history_undo called with a nonempty transaction (RhBug:878348)
Enable the "history undo" command.
Move transaction check error output into commands.
Add history-undo-specific transaction check error output.