Right now it can all be done with `clear`. You can either do `clear(color=True, depth=True)` or `clear(color=(0, 0, 0, 1), depth=1.0)` or any combination -- `bool` means do it, non-bool means set it then do it. However, it is nice to still have the option of setting without doing, which is what `set_clear_color` and `set_clear_depth` would be for. Personally I don't think it's too complex to have both -- what about just promoting the preferred way of doing it?