help: fix the display for `hg help internals.revlogs` (issue5227) It previously aborted saying the help section wasn't found. Credit to Yuya for figuring out the fix.

builddeb: add distroseries to tagged versions This is needed so that launchpad and friends have a unique version number for each distroseries (trusty, wily, xenial, etc). It was discovered when trying to upload 3.8 to launchpad.