Add a mouse event interface for use by HIDs that give coordinates in
absolute terms. The HID values are normalized to be between 0 and 1 by
dividing the reported values by the maximum values. These normalized
values are then translated in the GUI code into display values by
multiplying by the display dimensions as appropriate.

The previous code quit searching for a driver when a probe failure
used the throw mechanism to exit. This update to the USB probe code
allows the search for a driver to continue after the throw mechanism
is used. This change also required changing all of the calls of (throw
:probe-failed NIL) to (throw :probe-failed :failed) so that the throw
path can be distinguished from the normal failure exit of returning
NIL.

The HID driver was restructured to move the HID mouse driver to
hid-mouse.lisp and the HID keyboard driver stub to
hid-keyboard.lisp. (hid-keyboard.lisp contains a stub driver which
contains no real functionality.)

In addition, the HID report parser was re-written to more completely
and correctly parse the HID report and the HID mouse driver was
re-written to use this new parser output. These are major re-writes
and comparison with the previous code is probably not useful.

Merge the single report and multiple report code.

hid.lisp:
    Update comments to reflect data table in hid-keyboard.lisp.

hid-mouse.lisp:
    Change the way array report items are handled, instead of treating
    an array as a sequence of buttons, treat it as an array. This fits
    in better with keyboard reports where an array of characters is
    defined.

hid-keyboard.lisp:
    Implement the hid keyboard driver.