racket/gui win32: fix Space handling of buttons and checkboxes

Suppress WM_KEYDOWN messages to a button or checkbox, so that the
top-level window takes care of Space and Return for a button or
checkbox with the keyboard focus.

Closes PR 14710
racket/gui keymap: adjust handling of 'control, etc., events

If a keymap has a grab, then discard key events that are modifier
changes or key releases.

Adjusts commit 8ba8d01ec0 so that Ctl-u work in DrRackt (and
other framework-based programs).
fix dot layout when children are deleted

closes PR 14718
fix cross-module function inlining and argument use-count tracking

Order mismatch between tracking an use could cause a multiply-used
argument to be treated after inlining as a single-use argument.

Closes PR 14717
make installers: avoid dot-files (like ".gitignore") in installers

Closes PR 14716
distro-build/readme: adjust content of generated README files

Relevant to PR 14714

(I think the remaining suggestions in the PR are about the build
configuration.)
Windows installer: uninstall "collects"

Closes PR 14715, where Eli describes the repair

(Probably, the "collects" directory was missing from the uninstaller
list because "collects" moved under "lib" in an intermediate variant
of the directory organization.)
moved a manual test over
interpolation for recorded animation; for David for now
add the capability to dynamically adjust the edge label font
make font size changes also change the font of the edge
labels and the size of the arrow heads in traces

closees PR 14719
wrapped in new testing macro
added a watcher thread to check on animated gif creation
fix typo, Closes PR14720
Add edge-width option to tree-layout
Fix last commit for hv-alternating algorithm
fix module-code caching

Fixes a problem with c4508ad0d9, which disabled module-code
caching too often. A symptom of the disabled cache was that
running "math/scribblings/math.scrbl" would use twice
as much memory.
Fix PR14692
Revert "Fix PR14692"

This reverts commit 92d5408aa87043916644ec68d05b18cee2d21f69, because
it breaks the build due to recursive deps. (It also breaks if the core
is in the "racket" package.)
Fix typo in math/matrix docs.

Closes PR14721.