Created attachment 25176 [details] [review]
Patch that changes the lower bound of Z value used for multifinger detection from 0 to FingerHigh

I had run into situation when my taps on the left physical button of Synaptics touchpad ended in a right click.  This was very weird, but debugging revealed that the problem lies in the ClickFinger2 and multifinger detection: value of Z was raising from 0 to 1 or 2, so the code path that translates W values to the number of fingers were activated.  As Synaptics manual suggests, values lower than 10 usually correspond to the fingers situated slightly above touchpad, so this seem to be my case.  And since we're using FingerHigh everywhere to detect touches, it is natural to use this value to detect multifinger clicks.  The attached patch does this and works for me.