Prep for testing. Need to be able to get the padding.
Move paddingDistance to public API.

We need to be able to get the padding distance for tests, and it *may* be helpful to others. I can't think of any reason this shouldn't be public API.
Work on RSColorPickerView-setSelection tests. Looks like there might be a bug, as one of them fails currently.
/cc @unixpickle