minor fix to Redex docs
fix treatment of an old-style ".plt" file as a package
raco setup: fix command-line argument handling
improve line number redrawing

it now checks to avoid drawing the line numbers when
the invalid region is not lined up in the X direction
add place-images and place-images/align
more helpful message for contract failure
Fixing PR14007
Track checksum errors
Fix checksum goof
Conservative extension to match so that app patterns may produce and consume multiple values.
Add 'distributed-places' to 'main-distribution'.
fix printing for vector contracts
tweaks to try to get more information on a new error in case it happens again
contracts & units are not getting along; unbreak the build for now
Add redex enum support for simple named repeats
Remove unnecessary names before enumerating.
Follow 480afa4c4de10ff428521405b6b9718a1edba055 in deinprogramm.

Abstract out the teachpacks dialog and re-use in DMdA languages.
Add (very simple) type for `hash`.
fix the conversion to a [0,360) interval for angles in 2htdp/image

closes PR 14071
Fix TR constructor detection.

Was accidentally turning #%expression into #%plain-app in some cases.