added optional <zproxy> element to config file, containing any of these attribute...

added optional <zproxy> element to config file, containing any of these attribute combinations (all three examples are semantically equivalent)
<zproxy host="localhost" port="9000"/>
<zproxy host="localhost:9000"/>
<zproxy port="9000"/>
This <zproxy> info is overruled by the '-z' command line switch
Removed a zillion compiler warnings coming from missing or dirty casts, mostly involving (xmlChar *) or (const char *)