Exiv2

When I try to run CMake, I get the following error

-- Performing Test ICONV_COMPILES
-- Performing Test ICONV_COMPILES - Failed
-- Could NOT find ICONV (missing:  ICONV_TEST ICONV_INCLUDE_DIR ICONV_COMPILES)
-- Found ZLIB: ../../zlib-1.2.7/$(ConfigurationName)/zlib (found version "1.2.7.1")
-- Found EXPAT: ../../expat-2.1.0/Release/expat
-- Could NOT find ICONV (missing:  ICONV_TEST ICONV_INCLUDE_DIR ICONV_COMPILES)
.........
-- ------------------------------------------------------------------
-- exiv2 0.23 configure results        <http://www.exiv2.org>
-- Building PNG support:               YES
-- Building shared library:            YES
-- XMP metadata support:               YES
-- Building static libxmp:             YES
-- Native language support:            YES
-- Conversion of Windows XP tags:      YES
-- Nikon lens database:                YES
-- Commercial build:                   NO
-- Build the unit tests:               YES
-- Building translations files:        NO
-- ------------------------------------------------------------------
-- MSVC -> forcing use of dynamically-linked runtime.
CMake Error at xmpsdk/CMakeLists.txt:21 (GET_TARGET_PROPERTY):
  Cannot find source file:

    ../../expat-2.1.0/Release/expat

  Tried extensions .c .C .c++ .cc .cpp .cxx .m .M .mm .h .hh .h++ .hm .hpp
  .hxx .in .txx

-- MSVC -> forcing use of dynamically-linked runtime.
-- MSVC -> forcing use of dynamically-linked runtime.
-- Configuring incomplete, errors occurred!

I resolved the problem with the patch applied. Since the EXPAT-libraries are already linked later on, there is no need to add them to that xmp library.

With this patch, and the reverted patch of Issue 844, I was able to compile the exiv2lib/exiv2 subprojects. Anyways the tests did not build, but that's another issue. Just verify that my patch doesn't break them on other platforms ;)