Changelog:
1) If scrollback is initialised with a negative nubmer then negate it
rather than setting it to 0. Should not hurt anyone, and might even make
some people's stuff work (eh, Scott??)
2) Microsoft exchange chat server doesn;t recognise the -w flag for wallops
so I have added the "-nowallops" option to networks/servers so that it
won't get sent (and the button will not appear either)
c2ba58d307