Sync zlib sources with GCC, upgrading to 1.2.10.

Changes in 1.2.10 (2 Jan 2017)
- Avoid warnings on snprintf() return value
- Fix bug in deflate_stored() for zero-length input
- Fix bug in gzwrite.c that produced corrupt gzip files
- Remove files to be installed before copying them in Makefile.in
- Add warnings when compiling with assembler code

Changes in 1.2.9 (31 Dec 2016)
- Fix contrib/minizip to permit unzipping with desktop API [Zouzou]
- Improve contrib/blast to return unused bytes
- Assure that gzoffset() is correct when appending
- Improve compress() and uncompress() to support large lengths
- Fix bug in test/example.c where error code not saved
- Remedy Coverity warning [Randers-Pehrson]
- Improve speed of gzprintf() in transparent mode
- Fix inflateInit2() bug when windowBits is 16 or 32
- Change DEBUG macro to ZLIB_DEBUG
- Avoid uninitialized access by gzclose_w()
- Allow building zlib outside of the source directory
- Fix bug that accepted invalid zlib header when windowBits is zero
- Fix gzseek() problem on MinGW due to buggy _lseeki64 there
- Loop on write() calls in gzwrite.c in case of non-blocking I/O
- Add --warn (-w) option to ./configure for more compiler warnings
- Reject a window size of 256 bytes if not using the zlib wrapper
- Fix bug when level 0 used with Z_HUFFMAN or Z_RLE
- Add --debug (-d) option to ./configure to define ZLIB_DEBUG
- Fix bugs in creating a very large gzip header
- Add uncompress2() function, which returns the input size used
- Assure that deflateParams() will not switch functions mid-block
- Dramatically speed up deflation for level 0 (storing)
- Add gzfread(), duplicating the interface of fread()
- Add gzfwrite(), duplicating the interface of fwrite()
- Add deflateGetDictionary() function
- Use snprintf() for later versions of Microsoft C
- Fix *Init macros to use z_ prefix when requested
- Replace as400 with os400 for OS/400 support [Monnerat]
- Add crc32_z() and adler32_z() functions with size_t lengths
- Update Visual Studio project files [AraHaan]

zlib/examples/gun.c

@@ -46,7 +46,7 @@
    end-of-file, they cannot be concantenated.  If a Unix compress stream is
    encountered in an input file, it is the last stream in that file.
 
-   Like gunzip and uncompress, the file attributes of the orignal compressed
+   Like gunzip and uncompress, the file attributes of the original compressed
    file are maintained in the final uncompressed file, to the extent that the
    user permissions allow it.
 

zlib/examples/gzlog.c

@@ -1,6 +1,6 @@
 /*
  * gzlog.c
- * Copyright (C) 2004, 2008, 2012 Mark Adler, all rights reserved
+ * Copyright (C) 2004, 2008, 2012, 2016 Mark Adler, all rights reserved
  * For conditions of distribution and use, see copyright notice in gzlog.h
  * version 2.2, 14 Aug 2012
  */
@@ -243,7 +243,7 @@ typedef unsigned int uint;
 typedef unsigned long ulong;
 
 /* Macro for debugging to deterministically force recovery operations */
-#ifdef DEBUG
+#ifdef GZLOG_DEBUG
     #include <setjmp.h>         /* longjmp */
     jmp_buf gzlog_jump;         /* where to go back to */
     int gzlog_bail = 0;         /* which point to bail at (1..8) */

zlib/examples/zran.c

@@ -27,7 +27,7 @@
    grows as needed to accommodate the points.
 
    To use the index, an offset in the uncompressed data is provided, for which
-   the latest accees point at or preceding that offset is located in the index.
+   the latest access point at or preceding that offset is located in the index.
    The input file is positioned to the specified location in the index, and if
    necessary the first few bits of the compressed data is read from the file.
    inflate is initialized with those bits and the 32K of uncompressed data, and