Smooth scrolling again

[Max Schwarz]

Hi,

I implemented most of the dynamic-resolution feature today.
Patches are at https://github.com/x-quadraht/pscroll/tree/master/patches/ .

The wheel resolution property now resides in the emuWheel.c code, which 
reflects that it only affects wheel emulation. I added a manpage entry, too.

Currently I'm calling ChangeMasterDeviceClasses() for sending out change 
events in InitValuatorAxisStruct(). Should I send out a change event just for 
the device as well or is that enough?

Peter pointed out that I would need to generate DevicePresence events for the 
changed devices to support pre-XI2 clients, but do they even get the 
resolution field?

Max