Change -g to -f ("flat" totals).
Revamp totals output: sum groups and show indented (except with -f option).
Implement --timewarp option, useful for test suite.
Add 'WARP TO ...' keywords to test suite, using --timewarp option.
fix remove_timing(): don't forget to save removal to file.
fix new tickoff implementation.
totals diffing: do not barf on None != 0.
Tweak test suite to match changed output.
New test script: tickoff.