This adds a --until_complete flag to the db archive command, which will
attempt to run batches of max_rows continuously until archiving has
completed (or stops being able to archive anything). We also take care
to catch KeyboardInterrupt so that it will, if stopped, still print
the verbose report at the end. Instead of printing the table on each
iteration, we print some progress information and then provide a completed
summary table at the end of the run.
This also defaults max_rows to a sane value. The previous meaning of not
providing a value was "archive a whole table in a single operation",
which was useful only in the most simple of cases. Now that we have
a more reasonable "do it until you are done" mechanism, we default this
to 1000 rows for sanity, which also serves as the batch size for the
continuous mode.
Implements blueprint archive-deleted-rows-all
Change-Id: I2929c2f5b3116b63a4666b258bf078bc51d4e45a
6f00d3be95