Issue: #940.  Fixed compilation warning in MinGW

git-svn-id: svn://dev.exiv2.org/svn@3220 b7c8b350-86e7-0310-a4b4-de8f6a8f16a3
version.cpp: fixed how compiler detect for shared/static linking

git-svn-id: svn://dev.exiv2.org/svn@3221 b7c8b350-86e7-0310-a4b4-de8f6a8f16a3
Issue: 940.  Fix Cygwin compilation warnings.

git-svn-id: svn://dev.exiv2.org/svn@3222 b7c8b350-86e7-0310-a4b4-de8f6a8f16a3
Change to r3221 for clang

git-svn-id: svn://dev.exiv2.org/svn@3223 b7c8b350-86e7-0310-a4b4-de8f6a8f16a3