the CLI functions we hit the fact that the evbuffer functions in libevent
are not properly constified.

It's better to deconst the error messages and just "let it be known" that
argv[0] is const (or NULL).



git-svn-id: http://www.varnish-cache.org/svn/trunk/varnish-cache@110 d4fa192b-c00b-0410-8231-f00ffab90ce4