Distinguish between left and right modifier keys

[Manderby]

Very low priority task. Following removed comments might help:

//    [event modifierFlags]; NSEventModifierFlagCapsLock;
//    let isLeftShift = event.modifierFlags.rawValue & UInt(NX_DEVICELSHIFTKEYMASK) != 0
//    let isRightShift = event.modifierFlags.rawValue & UInt(NX_DEVICERSHIFTKEYMASK) != 0

Note that distinguishing might not be possible depending on the system.

[Manderby]

On windows, the following link might help: https://stackoverflow.com/questions/5920301/distinguish-between-left-and-right-shift-keys-using-rawinput