Kudos for the new vtl2 ctrls framework

[Hans de Goede <hdegoede@redhat.com>]

Hi all,

After making some serious use of it in the pwc driver cleanup
I would like to thank Hans V. for all his hard work on the
new ctrl framework.

The clusters bit got a bit getting used to / but once I did
it is great.

Once you get it, it really makes sense to group certain ctrls
into clusters which then get set in a single call to the driver,
allowing more or less atomic handling of things like autofoo +
foo changing. And in the pwc case also grouping the pan and
tilt controls, which get set with a single usb command,
so that with s_ex_ctrls an app can in theory do diagonal
moving of the camera rather then stair case moving.

Thanks Hans V.!

Regards,

Hans