Add support to build and test i386 releases.
Add configs to run i386 tests.

This shards the config files into per-machine directories.  kyua1 is left
to run amd64 tests and kyua2 to run i386 tests, for now at least.
Fix creation of the 0-LATEST directory.

I'm not exactly sure why it was broken in an odd way though, but this
seems to fix it.  Should take a closer look later.
Install pkgconf into the VM.

A couple of atf tests require pkg-config to run, so install pkgconf into
the VM.