most notable in error report from 'del' applet

noticeable fixes upgrading of packages which get pulled in only
by install_if rule. this also simplifies the inheritance calculation
for packages, as well as the place where it is done for install_if
triggered packages.

'available' really means 'available in one or more configured
repository'. Cache is not a repository we track, so those are
only available for installation, but not available as preferred
to be installed from repository. fixes #2831.

fixes #2113

This implements a new protected path flag '!' to include always
matching entries in the backup mode (overlay). This is also turned
on for etc/apk to include everything there in overlay, because
the full list of repositories and signing keys need to be in
overlay - just getting them from a package is not enough during
bootstrap.

This reverts commit a99bedba.

Simply print the default arch and exit.
This is so scripts don't need to parse the output of -V.

Prevent the progressbar and status messages to mess up stdout.

Makes it more useful whith pipes.

stdout is the proper place for it. this also fixes the progress
bar in musl, which seems to not support using line buffering for
stderr.

http://ewontfix.com/11/

to not run any per-package scripts. useful for managing buildroot
when cross-compiling.

add also a test case for this

at least debian and musl do this, so let's go along with that.

This option lets us search for all package with given origin.

apk would try run the trigger even if package failed to install.

We should not disqualify non-selectable packages as it would mark it as
dirty, forcing it to reconsider the name again, which could end up in
an endless loop.

fixes #2135

fixes #2134