### <kbd>*-t* `arch`</kbd> package target

[Arch provides a mixed-mode package system. While allows port-style package building from source, the installs binary packages.

The fpm/xpm `-t arch` target crafts a .tar.xz archive, and embeds:

  - `.PKGINFO` a meta description ini file
  - `.MTREE` a bsdtar file

Generated tarballs don't carry a leading `./` for contained files. Otherwise this is a fairly standard target.

  - Dependencies are listed (take note that Arch pkgnames may differ).
  - License is just always listed as `'custom'`, no mapping yet defined.
  - Build dependencies aren't mirrored (no idea what those are, and fpm doesn't have any).
  - Owner/group ids are always set to root in the tarball.