[ltp] X1 Carbon Touch Coordinates

[Chris Schumann]

Peter asked for Linux compatibility issues and I have only one so far.

On my X1 Carbon Touch (running Fedora 20) while using the internal 
display and an external monitor, the touch screen input maps to the 
entire area of the combined displays instead of the area of only the 
touchscreen.

To be more clear, if I set up the external monitor to be to the right of 
the internal display, then tapping the left edge of the touchscreen 
clicks the left edge of the laptop display. However if I tap the right 
edge of the touchscreen, that clicks the right edge of the EXTERNAL display.

I hope this is easy to fix, but as a software developer I know that it 
could violate a key assumption built deep into a driver a long time ago.

I'm happy to run test and report results.

Best,
Chris