Adds `--from-dir' and `--from-install' flags to select the interpretation
of the argument as a directory or as the name of an installed package.
Relevant to PR 13669
Adds `--as-is' (the default), `--source', and `--binary' flags to
select a pruning mode.
The `raco setup' tool recognizes a `rendered-scribblings' specification
in "info.rkt" to trigger moving rendered documentation into place,
registering its tags in the cross-reference database, and fixing up
references to "local-redirect.js"; the presence of a "synced.rktd"
indicates when those fixups have been performed (since, if the package
is installed in a user-specific scope, the documentation doesn't actually
move anywhere). Finally, "out<n>.sxref" needs to report paths relative to
the documentation's directory, and then the relative-directory references
need to be suitably resolved at derserialization; some support for such
relative paths was in place, but it wasn't quite general enough before.
This change makes document building --- and specially incremental
document building --- more scalable. The global duplicate-definition
check is handled by a database query, for example.
The `xref' produced by `setup/xref' uses the database to delay
loading "out.sxref"s, which cuts 64-bit DrRacket's initial
footprint by around 50MB (i.e., about 20%).
