zlib: upgrade to version 1.2.5

zlib: upgrade to version 1.2.5

from 1.2.3
update homepage and license

changes:
  - remove 1.2.3.3 patch
  - breakdown autotools.patch to configure.ac and Makefile.am, update
    src in Makefile.am and use do_configure_prepend instead
  - remove README from LIC_FILES_CHKSUM because it duplicates zlib.h
    and also causes checksum to change for every release
  - remove visibility.patch: the purpose of the patch was to change
    "<type> ZEXPORT" to "ZEXPORT <type>", however:
     1. the use of ZEXPORT and ZEXTERN have been changed a lot in
        zlib, there is no changelog to indicate which version was
        the patch based on and its rationale
     2. zlib used to set default visibility to `hidden'
        (-fvisibility=hidden), and override external symbols with
        `default' visibility, it had caused a lot of problems on
        different platforms. But starting from 1.2.5, default
        visibility is now `default', `hidden' visibility override
        has effect only for the correct GCC versions, most visibility
        related issues should have already been fixed

  http://mail.madler.net/pipermail/zlib-devel_madler.net/2010-April/002045.html

     3. as for now, ZEXPORT is used in Win/BeOS only, and can expand
        to WINAPI or __declspec(dllexport), both of which should be
        put behind return type, so there is no need to patch

     In conclusion, the patch is not applicable for the current release,
     so it's removed

Signed-off-by: Qing He <qing.he@intel.com>