test-equal->test for better drdr source loc info
Fixes PR13655
Fixing PR13657
A few links
fix non-terminal reference
get a better name for certain contract error messages

related to PR 13665
fix bad call to raise-argument-error and use ->i instead of ->d
for the mixin contracts
extend proc-doc to support optional arguments in an ->i contract

also refactor to be able to add some unit tests
make the get/extend extension more flexible

Specifically, allow a name to be specified with an
extension such that subsequent uses of those extensions
will replace mixins instead of adding new ones
Tally Maze
Go to a 12x12 maze to make it slightly easier to win
New Racket version 5.3.3.9.
fix ->m for keyword arguments

closes PR 13674
fix box/c and vector/c obligations

closes PR 13673
Adding documentation notes re Eli
Post-release version for the v5.3.4 release