BLF: replace global aa pref w/ monochrome flag

Now disabling anti-aliasing doesn't impact sequencer, render stamp etc.

source/blender/python/generic/blf_py_api.c

@@ -461,6 +461,7 @@ PyObject *BPyInit_blf(void)
 	PyModule_AddIntConstant(submodule, "SHADOW", BLF_SHADOW);
 	PyModule_AddIntConstant(submodule, "KERNING_DEFAULT", BLF_KERNING_DEFAULT);
 	PyModule_AddIntConstant(submodule, "WORD_WRAP", BLF_WORD_WRAP);
+	PyModule_AddIntConstant(submodule, "MONOCHROME", BLF_MONOCHROME);
 
 	return submodule;
 }