tap-to-click feedback

[John Gilmore]

> we tried the synaptics driver initially (when we got the new
> touchpads) but by itself it caused extremely erratic (perhaps not
> erratic, exactly, but just way-too-fast) mouse cursor behavior. 

There seems to be something wrong with general Linux mouse behavior.
Even on ordinary optical mice (like the HP I'm using now), the mouse
works fine about 98% of the time; then it jumps to the top of the
screen inappropriately.  (Running Ubuntu Jaunty with 2.6.28-11-server
kernel.)

I'd noticed this with touchpads and assumed it was a buggy touchpad,
but it seems to be a more generic bug somewhere in Linux.

The latest Ubuntu (karmic beta) disables tap-to-click by default,
which is a regression (see
https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-input-synaptics/+bug/378391
with it's more-than-a-dozen duplicates and see also #441013).  It
turned out that there was a lot of complicated interaction behind the
scenes that would make it work, fail, work, fail, ... with different
versions of various packages.

	John