runtime_loader: only add ABI directories to system library paths

It only makes sense to add the ABI directories to library paths
created by Haiku itself. E.g. on a gcc2h build, appending x86.

This also fixes build issues where LIBRARY_PATH is amended, and
the target binaries and libraries are in different locations.

Note: the develop lib directories were excluded, as runtime_loader
shouldn't be looking at these in the first place.
Some more packages

- libao updated
- libid3tag (for MPD)
- pciutils (for flashrom)
- links