scribble/decode: document treatment of whitespace by `decode-content`
raco pkg install: fix tmp-directory clean-up

Fix when installing from a non-directory in `--source` or
`--binary` mode, and fix clean up of a GitHub-generated archive
when using a path within the archive.
raco pkg install: change interpretation of archive with a single directory

When an archive used as a package source has all of its content
within a single top-level directory, then treat that directory's
content as the package content, instead of treating the directory
itself as the package content.

The change makes "x.zip" created with

  zip -r x.zip x

work the same as "x" as a package source. It also makes a ".zip"
for a package's GitHub repository (from clicking the "Download ZIP"
button) work the same as the repository.

This change is backward incompatible, but it's unlikely to break
any working package (since that would be a single-collection package
that provides only a subcollection).
raco setup: fix PLTCOMPILEDROOTS handling when checking pkg deps

Closes PR 14540
Don't lose syntax locations for TR define

Closes PR 14544
raco setup: fix for relative & multiple paths in PLTCOMPILEDROOTS

Fix the part of `raco setup` that deletes ".zo" files that
have no corresponding source.
document and deprecate 3-argument call to default module name resolver

Calling the default module name resolver with three arguments logs an
error message. The intent is that 3-argument support will be removed,
eventually.
syntax/docprovide: fix direct call to module name resolver

Also, deprecate the library.
mzcom doc improvements
fix many more 3-argument calls to the module name resolver
unbreak drracket

A conversion in 2f46525a7d was wrong.
win32: repair for VS Studio build

Thanks to Gustavo Massaccesi

Closes PR 14555
Fix printing for certain list types with a mu var

Closes PR 14552
Disallow non-productive PolyRow types

Closes PR 14554
Adjust TR error message for consistency

The non-productive type check in type parsing and in type
alias setup should produce the same failure messages.
Make tc-expr the same implementation as tc-expr/check.
Remove conditional tc-expr/check splits that no longer need to exist.
Remove tc-body, and 0 arg case in tc-body/check.
Remove tc/app/check.
Remove tc/lambda/check.