Change our chosen "bad_ip" to 192.0.2.255 which is a broadcast address from RFC5737's TEST-NET-1 and put a comment there to explain.
Change our chosen "bad_ip" to 192.0.2.255 which is a broadcast address
from RFC5737's TEST-NET-1 and put a comment there to explain.

I fear this is a loosing battle, but at least this is more "official"
than the previous "10.255.255.255" choice.

Fixes #1159

ajasty-cavium/Varnish-Cache,zhoualbeart/Varnish-Cache,1HLtd/Varnish-Cache,gquintard/Varnish-Cache,gauthier-delacroix/Varnish-Cache,gauthier-delacroix/Varnish-Cache,zhoualbeart/Varnish-Cache,mrhmouse/Varnish-Cache,varnish/Varnish-Cache,ajasty-cavium/Varnish-Cache,alarky/varnish-cache-doc-ja,gauthier-delacroix/Varnish-Cache,1HLtd/Varnish-Cache,alarky/varnish-cache-doc-ja,feld/Varnish-Cache,franciscovg/Varnish-Cache,1HLtd/Varnish-Cache,feld/Varnish-Cache,gquintard/Varnish-Cache,gauthier-delacroix/Varnish-Cache,feld/Varnish-Cache,zhoualbeart/Varnish-Cache,chrismoulton/Varnish-Cache,mrhmouse/Varnish-Cache,varnish/Varnish-Cache,franciscovg/Varnish-Cache,alarky/varnish-cache-doc-ja,franciscovg/Varnish-Cache,ajasty-cavium/Varnish-Cache,feld/Varnish-Cache,gauthier-delacroix/Varnish-Cache,alarky/varnish-cache-doc-ja,mrhmouse/Varnish-Cache,varnish/Varnish-Cache,chrismoulton/Varnish-Cache,franciscovg/Varnish-Cache,chrismoulton/Varnish-Cache,gquintard/Varnish-Cache,alarky/varnish-cache-doc-ja,zhoualbeart/Varnish-Cache,ajasty-cavium/Varnish-Cache,ajasty-cavium/Varnish-Cache,varnish/Varnish-Cache,gquintard/Varnish-Cache,feld/Varnish-Cache,1HLtd/Varnish-Cache,mrhmouse/Varnish-Cache,mrhmouse/Varnish-Cache,franciscovg/Varnish-Cache,zhoualbeart/Varnish-Cache,chrismoulton/Varnish-Cache,varnish/Varnish-Cache,chrismoulton/Varnish-Cache