zlib patch for DEBUG pre-processor

Patch as described on zlib:
https://github.com/madler/zlib/pull/80

PDF/include/Poco/PDF/deflate.c

@@ -93,7 +93,7 @@ local uInt longest_match  OF((deflate_state *s, IPos cur_match));
 #endif
 local uInt longest_match_fast OF((deflate_state *s, IPos cur_match));
 
-#ifdef DEBUG
+#ifdef ZLIB_DEBUG
 local  void check_match OF((deflate_state *s, IPos start, IPos match,
                             int length));
 #endif
@@ -1225,7 +1225,7 @@ local uInt longest_match_fast(s, cur_match)
     return (uInt)len <= s->lookahead ? (uInt)len : s->lookahead;
 }
 
-#ifdef DEBUG
+#ifdef ZLIB_DEBUG
 /* ===========================================================================
  * Check that the match at match_start is indeed a match.
  */

PDF/include/Poco/PDF/deflate.h

@@ -246,7 +246,7 @@ typedef struct internal_state {
     uInt matches;       /* number of string matches in current block */
     int last_eob_len;   /* bit length of EOB code for last block */
 
-#ifdef DEBUG
+#ifdef ZLIB_DEBUG
     ulg compressed_len; /* total bit length of compressed file mod 2^32 */
     ulg bits_sent;      /* bit length of compressed data sent mod 2^32 */
 #endif
@@ -294,7 +294,7 @@ void _tr_stored_block OF((deflate_state *s, charf *buf, ulg stored_len,
  * used.
  */
 
-#ifndef DEBUG
+#ifndef ZLIB_DEBUG
 /* Inline versions of _tr_tally for speed: */
 
 #if defined(GEN_TREES_H) || !defined(STDC)

PDF/include/Poco/PDF/zutil.h

@@ -238,7 +238,7 @@ extern const char * const z_errmsg[10]; /* indexed by 2-zlib_error */
 #endif
 
 /* Diagnostic functions */
-#ifdef DEBUG
+#ifdef ZLIB_DEBUG
 #  include <stdio.h>
    extern int z_verbose;
    extern void z_error    OF((char *m));