Many functions are 'public' in that they are in header files, but they don't need to be. The jabber.c ones were likely there because of the xmpp/gtalk multi-library thing that's gone now.
This removal is 'naive', in that if a prototype is necessary for now-static functions, then that's all I did, instead of any re-ordering.
I also left in some 'unused' data.c functions as their use was deleted when removing smileys and they may still be needed.

Compiled.