Support various type of controller buttons

[takahirox]

Currently only supports one trigger button. We should support more various type of buttons, for example Oculus Go tough pad(?).

Maybe related to #15

[takahirox]

Touch pad support #38

[takahirox]

Touch pad support has been removed for now #50 I might recover if needed later.

[takahirox]

A big concern is how UI should be for touch pad and other special buttons.

[checksummaster]

About button, with oculus touch, I should change some code like that (not so sure why then I don't make a pull request for this)
const BUTTON = {
SELECT: 1,
SQUEEZE: 2
};
before it was 0,1 but 0 is the thump (on the joystick)

[takahirox]

Thanks for the report. I will look into.

[takahirox]

@checksummaster I wanted to separate bug report issue from this feature request issue to track the problem more easily so I opened #237