[xml] Patch for enabling ZLIB support in Win32 build

["Daniel Gehriger" <bulk linkcad com>]

Hello,

I could not find a way to build libxml2 on Win32 with with zlib support
enabled. I modified the "configure.js" and "Makefile.msvc" to accept the
option "WITH_ZLIB". 

I attached a patch -- could you please add it to the distro ?

Thanks

Daniel

Attachment: zlib.diff
Description: Binary data