put search objects into a search class.

name tweaks: match -> match_list, match_repo -> match

tidy

unify object lookup as locator->match($o) or $repo->match($o)

lift PkgSpec creation up into PackingElement::Dependency.

use OO version of spec match

we want to no longer expose PackageLocator::available(), lift interfaces
up there, starting with match_spec.

restore lost behavior

refactor: create a solver object to handle state issues in a simpler way.

use one single list for system directories.

remove -Fboguslibs, we haven't had unmarked libraries for years

zap unused parameters.

share common code for system libs.

replace pkgbase with less confusing name localbase

$o->method() becomes $o->method

move common code into a find_candidate function.

refactor: remove temp @avail, move it to an external code, slightly more
explicit code.

kill code for handling old style dependencies.

update copyright years, standardize licence.
reword the introduction to the stuff originally from FreeBSD to clarify
slightly.

streamline messages for interactive mode, no need to repeat the same list
twice.

don't return undef, use plain return.
(return undef is only false in a scalar context)
found my perlcritic, one of the few issues I agree with...

less verbose listing of libraries

* New -i interactive option, that can ask obnoxious questions.
* move the signature code to a packing-list method, prepend the pkgname.
* depend on distant listings, cache these systematically.
* cut

* New -i interactive option, that can ask obnoxious questions.
* move the signature code to a packing-list method, prepend the pkgname.
* depend on distant listings, cache these systematically.
* cut the PKG_PATH at :/ systematically, much simpler than parsing URLs.
People should get used to trailing /s.
* let pkg_add -u actually run the update.
* check for signature in more places, for instance, let pkg_add installed_stuff
be a void operation.
* grab enough stuff during updates to check signatures, so that pkg_add -u
can report updates that are not needed right away, instead of waiting
for the more confusing `trying to update'
* beginning of @module support.
* @pkgpath support, including updates.
* systematically expand stems when applicable.
* use visitors systematically in pkg_info.
* pkg_info -S reports signature.
* remove hardcoding of categories in PackingList, so that future modules
will be able to expand them.
* add @updateset and @incompatibility keywords.

show more ...

bug fix: if default is not available, do not push it for installation.

split off the code that handles dependencies proper, so that we can (later)
reuse it in pkg_info or lib-depends-check.