no issue #
no issue #

fixing issues with liftover:
* last tilestep now should be outputting properly
* pathological checks

Arvados-DCO-1.1-Signed-off-by: Abram Connelly <abram@curoverse.com>

curoverse/l7g,curoverse/l7g,curoverse/l7g,curoverse/l7g,curoverse/l7g,curoverse/l7g,curoverse/l7g