A regression in 0.23 that the tests missed. Fixed by 0.23.1.
aregister: fix date filtering with disordered txns (fixes #184)
Fix a refactoring-related regression that the tests missed: if
transactions were not ordered by date in the journal, register
could include postings before the report start date in the output.
register: also fix date (or date2) sorting of postings (#184)