makechrootpkg: Split out chrootbuild into a function

Now syntax highlighting works properly! :D
arch-nspawn: Quiet systemd-nspawn again

systemd-nspawn always outputs some debug messages over stderr.
Both stdout and stderr from inside the chroot are sent through
a pty to stdout.
archbuild: Correct makechrootpkg argument order

The user-passed makechrootpkg_args may contain a "--" to pass
arguments to makepkg. In this case, the order is wrong.
makechrootpkg: Update comments to point out the bad hacks
makechrootpkg: Add hack for svn sources and makepkg 4.1.1
crossrepomove: copy packages locally

Nymeria's HTTP mirror is now password-protected and crossrepomove broke.