[CF-Devel] Fix for slowness of gtkclient when not connection to server

[Scott MacFiggen]

I found the gtk client annoying slow when it wasn't connected to a
server. I tracked it down to repeated calls to gtk_main_iteration
in get_metaserver. This is really really really slooow. 
gtk_main_iteration() is mostly there for use in really long running
functions that want to process UI input along the way. I changed it
to call gtk_main() instead and had enter_callback() call gtk_main_quit()
after the user entered a server to connect to. 

Changes are in CVS.

	-Scott