bind-input example weirdness

[elemoine]

http://openlayers.github.com/ol3/master/examples/bind-input.html

When rotating the map using Alt-Shift drag the rotation slider doesn't update as expected.

[twpayne]

I think the problem is that rotations outside the range 0..2π are not handled correctly: they are valid rotations but out of the range of the slider. To reproduce: from a reload, rotate clockwise to see the slider move, rotate anti-clockwise to see the slide clamp to zero (negative rotation).

Tested on Chrome, Firefox, and Safari on Mac OS X.

[twpayne]

Suggested workaround: configure the slider to use the range -2π..2π. This means that the slider will be in the center when there is no rotation and can cope with a full turn in either direction.

[twpayne]

Fixed by @tschaub in 4cec054 (direct merge to master).