nblendU8TowardU8 Helper Function

void nblendU8TowardU8( uint8_t& cur, const uint8_t target, uint8_t amount)
{
  if ( cur == target) return;

  if ( cur < target ) {
    uint8_t delta = target - cur;
    delta = scale8_video( delta, amount);
    cur += delta;
  } else {
    uint8_t delta = cur - target;
    delta = scale8_video( delta, amount);
    cur -= delta;
  }
}