Low-hanging fruit: Fix most warnings in lib/DtSearch.

Most of these are related to missing includes and prototypes as well as
parens/braces.  A few are also potential 64bit issues.

cde/lib/DtSearch/hencode.c

@@ -57,6 +57,7 @@
  */
 #include "SearchP.h"
 #include <errno.h>
+#include <stdlib.h>
 
 #define X_INCLUDE_STRING_H
 #define XOS_USE_NO_LOCKING