to match the package name

add a few missing libraries and a note for the need of $FONTCONFIG_FILE

other sections are supposed to use this macros and define a part. Having
a default here is useless and maybe confusing

This reverts commit 80673c8c.

All testnodes should have been updated by now, so this commit is no
longer needed.

/reviewed-on nexedi/slapos!419

/reviewed-on nexedi/slapos!416

/reviewed-on nexedi/slapos!415

/reviewed-on nexedi/slapos!408

isp data is from https://www.whoismyisp.org/ip
cn-t for china telecom, default one if isp is other value
cn-m for china mobile
cn-u for china unicom

fix rst syntax - second try

fix markdown syntax

from nexedi/slapos!408 (comment 66703)

as always, using wrapper is easier and more flexible