STRING_LIST deorbit burn completed

[Poul-Henning Kamp]

I have removed the remaining uses of STRING_LIST in the tree, and
made vmodtool.py be slightly annoying if it is used.

vmodtool.py will get more and more annoying about this over summer
and around august 1st, it will refuse to compile it.

The replacement is of course STRANDS.

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
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FreeBSD committer       | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.