tools: test addons also echo their arguments
doc: instead of a template, save the last announcement
add: drop an obsolete functional test
reorganise functional tests by command/topic
show posting dates in debug output
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.