Exiv2

From Udi Fuchs, also reported by Will Stokes:

I just tried to build exiv2 0.11 on mingw32 and had two problems.

The first is with zlib. I had to used the configuration option
--with-zlib=/opt/mingw32, but then the compiler still didn't find
zlib.h so I had to also use
'make CXXFLAGS=-I/opt/mingw32/include', which seems a bit annoying.

The other issue is that pngchunk.cpp uses 'uint' (twice) and it is not
defined. Replacing it with 'unsigned' solved the compilation problem,
but I'm not sure about run time issues.

Additional information:

Workaround:
When compiling version 0.11 on Windows with MinGW/msys, use the --without-zlib flag to the configure script to disable the newly added PNG support (which uses zlib).

Note:
PNG support is also not enabled when compiling on Windows with MSVC.