fixed warning and tests
eliminated bug introduced with latest revision

please add to 6.1.1.
Fix types for foldl and foldr with 3 lists.

Thanks to Jack Firth for the report.
Work around a type alias bug in framework types

The type alias analysis is unable to detect a rare kind
of type dependency and as a result initializes type aliases
in an order that doesn't work. Adding the extra `Class`
boilerplate here accommodates the analysis.

Please merge to v6.1.1
Make: Dependency Manager. Documentation fix.
Add missing parenthese.
Fix type for stx->list in typed/syntax/stx

Please merge to v6.1.1
Fix TR treatment of parent row in class types

This bug manifested in having extraneous class
members in a type for a class whose superclass
expression was a mixin application.
Fix Guide typo

Please merge to v6.1.1
Fix TR docs on #:implements in Class types

Please merge to v6.1.1
raco test: fix `-l`
raco test: show more of stderr on failure
syntax-color/lexer-contract: make random-test failure declare itself

Random tests that are implciitly injected into a program should
declare themselves as such when they fail. Otherwise, random
crashes are really confusing.
syntax-color/racket-lexer: fix problem with unclosed "| "

... where the whitespace character after "|" is non-ASCII.

This bug was found by random testing in `syntax-color/lexer-contract`.
racket/udp: adjust receive into a zero-sized buffer

The OS doesn't necessarily react to a zero-sized buffer the way
that `udp-receive!` is supposed to work, so provide only a
non-zero-sized buffer to the OS.
correct `register-finalizer` docs by clarifying prohibitions
pkg manage docs: clairfy in overview that a git repo tag is allowed
Inside Racket: document Windows-specific treatement of "UTF-16"
openssl: fix `ssl-load-default-verify-sources!` for Win64

Closes PR 14784

Merge to v6.1.1
Add a test for generating GUI contracts for TR