Some small fixes to get things compiling on solaris with cmake.

There are also some changes that need to be done to libmv but I'm 
leaving those out so I can get it patched upstream first.

(Only works with gcc/g++ if we want to use sun's compiler we would need
to get rid of all of our annonymous structs which I don't think
we want to do at this point, example:

typedef struct wmNDOFMotionData {
        union {
                float tvec[3]; // translation
                struct { float tx, ty, tz; };   // this would need to be fixed
		// something like this or something similar:
                struct { float x, y, z; } t;
                };
...
)

Kent

source/gameengine/Ketsji/KX_PythonInit.cpp

@@ -47,6 +47,12 @@
 #undef _XOPEN_SOURCE
 #endif
 
+#if defined(__sun) || defined(sun) 
+#if defined(_XPG4) 
+#undef _XPG4 
+#endif 
+#endif 
+
 #include <Python.h>
 
 extern "C" {