Fix GLEW_STATIC redefinition warnings

cmake/mxe.cmake

@@ -8,8 +8,10 @@ if((${CMAKE_CROSSCOMPILING}) AND (DEFINED MSYS))
     set(PLATFORM_LINUX 0)
     set(PLATFORM_OTHER 0)
     # All must be static, CBOT and GLEW too
+    set(BUILD_STATIC ON)
     set(CBOT_STATIC ON)
     set(GLEW_STATIC ON)
+    set(SNDFILE_STATIC ON)
 
     if (${OPENAL_SOUND})
         set(OPENAL_MXE_LIBS

src/common/config.h.cmake

@@ -12,7 +12,9 @@
 #define HAVE_CFLOCALECOPYCURRENT 1
 #endif
 
+#ifndef GLEW_STATIC
 #cmakedefine GLEW_STATIC
+#endif
 
 #cmakedefine OPENAL_SOUND