Correct slew mode toggling to respond only to mapped keystroke

Change the way that slew mode is toggled so that it only occurs when the specifically mapped key is pressed. For example, if key ‘Y’ is configured in the keyboard profile as ‘Toggle Slew Mode’ (which is the default setting) then pressing ‘Y’ with any of the ‘shift’ keys Ctrl, Shift, Alt, or any combination of these, will also toggle slew mode. I originally tried raising this as a bug, but my report was closed as this is apparently ‘by design’. However, this does not seem to be documented anywhere and is inconsistent with other keyboard mappings which differentiate between the single key and usage with one or more shift keys. This caused me a problem with an add-on that uses C/S/Y; the same add-on also uses C/S/N with which I had no problem - it’s just this one key specific mapping.