readdate: Fix traceback when nothing is consumed from the input text

Make prefix phrases to the times of day optional again, to satisfy the tests

Add test for 'feed the cat in 3 days'

readdate: Show the start and finish of the consumed section of the input

tests: Add support for checking the consumed part of the input

Correct (I think) notation to make optional phrases optional

(0) -10 -6 +6 tip

mercurial