Improve handling of size and orientation.

Some touch device drivers report the range of
ABS_MT_ORIENTATION as [0,1].  The Linux multitouch protocol
spec says that the 0 value should always be considered vertical.

Add a new 'box' calibration mode for size to handle the case
where width and height are being provided.  The 'diameter'
calibration mode is inadequate because it drops one of these
components.

Change-Id: I7bd744fdff95acd4044d295efe8bd7186dbe8061