Windows: fix reported exe name in "independent" launchers

For example, make `raco exe --wrong` show "raco" instead of "racket"
as the error-reporting program. Normally, only `raco` and `setup-plt`
are implemented as "independent" launchers, because it's needed for
bootstrapping.
setup/command-name: drop ".exe" in short form
scribble/manual: add `history`

Also, show supplying package in providing-package hover at
definition sites.
in-directory: add optional argument to filter directories
scribble & slideshow: move detail-change notes into docs
raco setup: fix dependency checking for "racket" package

Possibly, only "base" should depend on "racket", while the version
number of "base" should track the version number of "racket".