Add expat 2.1.0 for Windows, Mac, and for local Linux builds (use system expat otherwise)

lib-src/expat/CMake.README

@@ -0,0 +1,42 @@
+== How to build expat with cmake (experimental) ==
+
+The cmake based buildsystem for expat works on Windows (cygwin, mingw, Visual 
+Studio) and should work on all other platform cmake supports.
+
+Assuming ~/expat-2.1.0 is the source directory of expat, add a subdirectory
+build and change into that directory:
+~/expat-2.1.0$ mkdir build && cd build
+~/expat-2.1.0/build$
+
+From that directory, call cmake first, then call make, make test and 
+make install in the usual way:
+~/expat-2.1.0/build$ cmake ..
+-- The C compiler identification is GNU
+-- The CXX compiler identification is GNU
+....
+-- Configuring done
+-- Generating done
+-- Build files have been written to: /home/patrick/expat-2.1.0/build
+
+If you want to specify the install location for your files, append 
+-DCMAKE_INSTALL_PREFIX=/your/install/path to the cmake call.
+
+~/expat-2.1.0/build$ make && make test && make install
+Scanning dependencies of target expat
+[  5%] Building C object CMakeFiles/expat.dir/lib/xmlparse.c.o
+[ 11%] Building C object CMakeFiles/expat.dir/lib/xmlrole.c.o
+....
+-- Installing: /usr/local/lib/pkgconfig/expat.pc
+-- Installing: /usr/local/bin/xmlwf
+-- Installing: /usr/local/share/man/man1/xmlwf.1
+
+For Windows builds, you must make sure to call cmake from an environment where 
+your compiler is reachable, that means either you call it from the 
+Visual Studio Command Prompt or when using mingw, you must open a cmd.exe and
+make sure that gcc can be called. On Windows, you also might want to specify a 
+special Generator for CMake:
+for Visual Studio builds do: 
+cmake .. -G "Visual Studio 10" && vcexpress expat.sln
+for mingw builds do: 
+cmake .. -G "MinGW Makefiles" -DCMAKE_INSTALL_PREFIX=D:\expat-install 
+    && gmake && gmake install