This allows a device subclass to call the parent method after doing an initial
action, or even deliberately not call the *generic* parent method at all.
It also simplifies the plugins; you no longer have to remember what the plugin
is deriving from and accidentally clobber the wrong superclass method.
The end year is legally and functionally redundant, and more importantly causes
cherry-pick conflicts when trying to maintain old branches. Use git for history.
Quite a few plugins use HID commands to communicate with the hardware. At the
mement we have ~6 implementations of SET_REPORT and are soon to add one more.
Move this into common code.
