HTTPviaSD separate requests for button pressed and button released

If the HTTPviaSD allowed a second request to be specified for when the button is released we could implement dimming and other time based actions.

i.e. I wish to send a DimUpStart command when he button is initially pressed and a DumUpStop command when it is released.

Adding a slider button that passed it's 0 - 1 value would be cool too ;-)