distro-build: fix catalog dir creation for built packages
Synch German string constants with latest.
cleanups to old, broken test suite and some bug fixes it uncovered

also, fix any/c generator
fix raco test -c

closes PR 14494
fix a performance bug in drracket's REPL IO.

This one of those classic n^2-loop-that-should-be-linear bug. The fix
speeds up this program (when run in DrRacket) by about 1.75x:

  (for ([x (in-range 10000)])
    (display "abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz\n"))

The bug is fairly old too: I introduced this bug on March 6th,
2004. (Thanks, Sam, for making that old history accessible!)
Index atexit in the documentation, to make it easier to find for people coming from C
fix accidental disabling of thread-specific process-milliseconds
Scribble search, etc.: fix URL decoding

Use Javascript's decodeURIComponent() instead of unescape().

This repair makes searching for Unicode characters work from DrRacket
(e.g., via F1).
net/sendurl: improve docs on encoding in `send-url` and other functions
Add support for 1 sided contracts on Top types.
Correctly handle moving dotted vars to the dmap.
make new-∀/c and new-∃/c figure our their own names and have a better printing
add pict->argb-pixels and argb-pixels->pict
Fix subst-all contract.
racket/draw: faster (on some platforms) path for drawing a bitmap

The faster path applies in the common case of drawing a whole
bitmap, as opposed to a section of the bitmap.

Thanks to Laurent Orseau for tracking down this performance issue.
games/cards: add @2x card images

For both original and @2x, adjust images to use alphas for the corner,
instead of drawing with clipping, which avoids alignment problems on
an @2x display.
remove/adjust obsolete C preprocessor cases

Mac OS Classic and Palm ae long since unsupported.

TCP support implies sockets (since old Mac TCP is gone).

For what it's worth, make the build work without TCP support, although
no one ever builds that way.
faster path for TCP input

Avoid polling a file descriptor to determine whether it has bytes;
just try to read, and then go to epoll/kevent mode when available,
skipping a poll/select.
reduce calls to `current-process-milliseconds` on thread swap

Call `current-process-milliseconds` once per swap, instead of twice.
fix bug in insertion of guards to prevent use before definition