HID: add driver for Roccat Kone gaming mouse

This Patch adds support for Kone gaming mouse from Roccat.
It provides access to profiles, settings, firmware, weight,
actual settings etc. through sysfs attributes.
Event handling of this mouse differs from standard hid behaviour
in that tilt button press is reported in each move event which
results in strange behaviour if not handled by the driver.

This is a heavily reworked version of the previously introduced driver.
The changes include most of the previously raised concerns,
memory leak and other fixes, code cleanups, adoption of additional
achieved knowlege about the hardware and is (IMHO) a much better version
than before even when I exchanged reduced USB-IO with a bigger memory
consumption.

I refused to implement one mentioned point:
Removing the 'just-because-we-can' attributes. Motivation:
Reading the clipped in weight: I'm no gamer and can't determine the
usefulness of this feature but if the manufacturer implements such a
feature it might make sense to someone and I would unwillingly limit the
functionality besides its such a small feature.
Reading the actual profile and dpi settings: Here I can testify that one
can get lost of the actual settings when switching back and forth.
The manufacturers windows driver has the ability for on-screen-display
of the values and there is a mouse in the market that has an lcd on the
underside of it to show these values. So I think this feature makes sense
not only for me and shouldn't be removed.

Signed-off-by: Stefan Achatz <erazor_de@users.sourceforge.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>