Merge pull request #37 from 123marvin123/master

fix for building on mac OS X

Author: fallahn

CMakeLists.txt

@@ -11,7 +11,7 @@ set(TMX_BUILD_EXAMPLE FALSE BOOL CACHE BOOL "TRUE to build the tmx-loader exampl
 set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_SOURCE_DIR}/cmake/Modules/")
 
 # tmx-loader uses C++11 features
-if(CMAKE_COMPILER_IS_GNUCXX)
+if(CMAKE_COMPILER_IS_GNUCXX OR ${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
 	set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")
 endif()