vive trigger/axes processing prevents continuous values

[grrrwaaa]

The way the trigger and axis handling is done in the openvr binding captures an instantaneous value, rather than the current actual value of the trigger/axis; setTriggerValue() is only called if the trigger touch state changes. This doesn't match how the oculus binding is done, where setTriggerValue() is called every time.

More importantly it doesn't allow a continuous sampling of the trigger or axis state, which is weird.

(Also, the difference between touch and press events is not captured by the Cinder-VR binding at the moment.)

[grrrwaaa]

Put a fix in my fork here, let me know if you want a pull request.
worldmaking@fb9ef6a

[chaoticbob]

Pull request would be awesome!

[grrrwaaa]

OK I will do, but not just yet -- seems like I'm still not getting continuous data. Hope to get time today to figure out why but otherwise it may be next week.