grim/purple-signals

moved everything to it's own files, fixed the build system for it, still failing miserably at actually making this work
#ifndef PURPLE_SIGNALS_H
#define PURPLE_SIGNALS_H
#include <glib.h>
#include <glib-object.h>
G_BEGIN_DECLS
gulong purple_g_signal_connect(GType t, const gchar *n, GCallback cb, gpointer d);
G_END_DECLS
#endif /* PURPLE_SIGNALS_H */