patch 8.1.1989: the evalfunc.c file is still too big

Problem:    The evalfunc.c file is still too big.
Solution:   Move f_pathshorten() to filepath.c.  Move f_cscope_connection() to
            if_cscope.c.  Move diff_ functions to diff.c.  Move timer_
            functions to ex_cmds2.c.  move callback functions to evalvars.c.
diff --git a/src/proto/if_cscope.pro b/src/proto/if_cscope.pro
index f9919c4..0dcfc76 100644
--- a/src/proto/if_cscope.pro
+++ b/src/proto/if_cscope.pro
@@ -7,6 +7,6 @@
 int cs_fgets(char_u *buf, int size);
 void cs_free_tags(void);
 void cs_print_tags(void);
-int cs_connection(int num, char_u *dbpath, char_u *ppath);
+void f_cscope_connection(typval_T *argvars, typval_T *rettv);
 void cs_end(void);
 /* vim: set ft=c : */