This is to avoid scan dlopen'ed plugins.

We scan any rpath set by any subpackage from same apkbuild. If it depends
on rpath to other package, developer will have to add that to ldpath.

This change means we have to move generation of .provides-so and .needs-so
til after all .rpaths are generated.

This changes the format of .provides-so file. We now add a column with
the version number

So it is not treated as a special 'virtual'
We use version number 0 for now.

some package (alpine-baselayout) needs to create /usr/local/bin etc.

POSIX only requires that filedesriptors 0-9 are available for shell
redirections.

was totally broke.

This reverts commit e045c451.

we depend on curl instead

use the abuild-sudo tool instead

fixes #951

mini sudo that checks if user is in "abuild" group and allows it to
run apk, adduser adn addgroup as root

ref #951

fixes #955

For a second, indented message line.

We need locking Since the build servers use a shared download dir
and multiple vservers might want download same file at same time.

fixes #873

So we can set pkgname if it differs from download archive name

curl does not fail by default. it downloads the 404 error page instead
so we need add -f option to curl.

Not been used for ages.

fixes #871