initial commit of wide-dhcpv6-20080615
patch from OpenBSD port

don't open the routing socket
patch from OpenBSD port: tweak client configuration
Patch from OpenBSD port: tweak server conf
Merge from OpenBSD port:

Rename dprintf function to debugprintf so as to not conflict with POSIX
function name.
add .gitignore
BSD build system
use arc4random() everywhere
Remove compat goo
Get rid of unused pre-processour directives
Unifdef HAVE_STDARG_H
unifdef HAVE_SYS_TIME_H and TIME_WITH_SYS_TIME_H
Unifdef __FreeBSD__ _linux _sun __sun__ and __KAME__

The latter *is* defined.
Un-_P() *.h
Un-_P() lex/yacc sources
un-_P() *.c
Merge README.md from github