raco pkg catalog-archive: handle interrupted update

While `catalog-archive` cannot handle arbitrary corruption of
a previous archive run, it should be able to handle a state
due to interruption or other transient errors.

Merge to v6.1.
(cherry picked from commit 42aeae24be5fd91c6f432b993f0167ea03cd1371)
fix misspelling tracker

please include on the release branch
(cherry picked from commit 83a76027d558a2c72996028dd846310b57f38ac1)
fix uses of uninitilized memory

Thanks to memcheck. (I'm unable to get far with Racket and memcheck,
but I get this far.)

Merge to v6.1.
(cherry picked from commit 45eb084d27be46bcd70ee05e1d07566e20aa1bc1)
fix order of file close and kqueue de-registration

Thanks to memcheck.

Merge to v6.1.
(cherry picked from commit 8559192944d4a19d75b1e3d77d230d269dff7654)
fix f1 and switch-tab keybindings when "Treat alt key as meta"
preference is set

closes PR 14629

please include on the release branch
(cherry picked from commit ae1349a906c02407dbb2b76f9c47d791e9396697)
fix esc;n keystroke in REPL

closes PR 14631

please include in release branch
(cherry picked from commit 3831496bf9b1e4728c0f3a6e1298ecfe5382492d)
raco setup: reorganize command-line flags

Group flags and refine the descriptions and documentation.

Merge to v6.1
(cherry picked from commit 95a126b2e15efcc58cb21ec93abaf9b92bfcb071)
reference: clarify significance of order for submodules

Merge to v6.1
(cherry picked from commit e044e4360b083a1c94c949da53d907f09f394bc7)
fix doc typo

Closes PR 14626

Merge to v6.1
(cherry picked from commit b3dd3954fb2e438990b564d095204bb7d719ec2f)
compiler/zo-structs: document `undef-ok?` in `assign`

Closes PR 14622

Merge to v6.1
(cherry picked from commit a479f18c28c9d1355d5029daa98fe781ff21f187)
fix GC-cooperation bug in `vector->values`

The `vector->values` function set up multiple return values
badly in the case that the given vector is chaperoned.
The problem could lead to NULL as results for `vector->values`.

Merge to v6.1
(cherry picked from commit f57c1c8e2a3b4d084816e904005ffbd71e2dec86)
Fix _date to allow dates before 1970 year
(cherry picked from commit 7d65ee6127b5d5f9e143114b3952df890dbec090)
ffi/unsafe/com: convert to `date*`, document limitations

Merge to v6.1 along with 7d65ee6127.
(cherry picked from commit 689f449c8de2dd911ba149e59ae784e5572b7302)
JIT: fix array-size expression that is handled badly by xform

This bug (in xform, really) appears to be responsible for recent "JIT
buffer overflow" crashes. It could also cause other memory-corruption
crashes.

The bug could be triggered by any program that uses operators like
`+`, `<`, and `bitwise-ior` on more than 2 and less than 6 operands
(which is a lot of programs), but only if a certain allocation and
GC pattern happens at just the right time (which is why a crash was
relatively rare).

Merge to v6.1
(cherry picked from commit c72f441d93464fa9022cedaa25f6ecf9037dd432)
xform: fix bad parsing of array sizes

A size expression N+M for a literal integer N was parsed as just N.
Report an error when that case happens (since it's difficult to
handle) instead of mishandling it.

Merge to v6.1
(cherry picked from commit e063b654fa03f2ba2ba0d0c5e9913ffa627b1ed6)
pkg/lib: make `pkg-directory->additional-installs` use 'compile-omit-paths

Otherwise, "test/pkgs" claims to provide various documents and executables
that are in test packages.

Merge to v6.1
(cherry picked from commit a70b3173b24e54fa0ddd8dde2a329d8133c27486)
pkg/lib: fix `pkg-directory->additional-installs`

Merge to v6.1 (with a70b3173b2)
(cherry picked from commit add04001cdb806dcc7bc00eac1139d1d38a7f02b)
change 'jump to next misspelled word' shortcut to avoid
conflicting with the close window shortcut (which is only
<menukey>-shift-w when there are multiple tabs open)

Merge to 6.1, please
(cherry picked from commit ec0ccbe35e3085657a455262c280f14e79b2f515)
spell check pict docs

Merge to 6.1, please
(cherry picked from commit 34b4472d97f3591f64c0807e2c117c17f4368e89)
fix a bug uncovered by  1b3fd890adb725

Merge to 6.1, please
(cherry picked from commit 6d2dfbff9e30a7917ff38a3a5e8a1c0455043df5)