Enable color diagnostics for GCC 4.9.1+.

CMake/Modules/Urho3D-CMake-common.cmake

@@ -688,6 +688,12 @@ else ()
         if (DEFINED ENV{TRAVIS} AND "$ENV{LINUX}")
             add_definitions (-D__extern_always_inline=inline)
         endif ()
+    else ()
+        # GCC-specific
+        if (CMAKE_CXX_COMPILER_VERSION VERSION_GREATER 4.9.1)
+            set (CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fdiagnostics-color=auto")
+            set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fdiagnostics-color=auto")
+        endif ()
     endif ()
 endif ()
 # LuaJIT specific - extra linker flags for linking against LuaJIT (adapted from LuaJIT's original Makefile)