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

drivers/unix/os_unix.cpp

@@ -32,10 +32,10 @@
 
 #ifdef UNIX_ENABLED
 
+#include "core/config/project_settings.h"
 #include "core/debugger/engine_debugger.h"
 #include "core/debugger/script_debugger.h"
 #include "core/os/thread_dummy.h"
-#include "core/project_settings.h"
 #include "drivers/unix/dir_access_unix.h"
 #include "drivers/unix/file_access_unix.h"
 #include "drivers/unix/net_socket_posix.h"