Resolve many build warnings

This patch fixes many warnings from the beginning of the build up to
and including the depend stage. Nearly all warnings should be gone
even with -Wall.

cde/programs/dthelp/parser/pass2/util/context.c

@@ -169,7 +169,7 @@ delim.h.
 #include "cont.h"
 
 /* Main procedure */
-void main(argc, argv)
+int main(argc, argv)
   int argc ;
   char **argv ;
 {