Reorganized core/ directory, it was too fatty already

-Removed FuncRef, since Callable makes it obsolete
-Removed int_types.h as its obsolete in c++11+
-Changed color names code

modules/mono/mono_gd/support/android_support.cpp

@@ -44,7 +44,7 @@
 #endif
 
 #include "core/os/os.h"
-#include "core/ustring.h"
+#include "core/string/ustring.h"
 #include "platform/android/java_godot_wrapper.h"
 #include "platform/android/os_android.h"
 #include "platform/android/thread_jandroid.h"