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/config/cf/OpenBSD.cf

@@ -1048,6 +1048,8 @@ CXXDEPENDINCLUDE != echo | `CcCmd -print-prog-name=cc1plus` -v 2>&1 | \
 #define LibraryCplusplusOptions	-Wall -Wpointer-arith -Wno-unused -Wno-write-strings -Wno-switch
 #endif
 
+#define DependFileName		.depend
+
 #define ArchitectureDefines    -DOPENBSD_ARCHITECTURE
 
 #define BuildLibPathVar        LD_LIBRARY_PATH