#12323 mousewheel (rebased onto dev_5_0)


This is the same as gh-2657 but rebased onto dev_5_0.

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**Cross OS & web browsers testing**

ticket http://trac.openmicroscopy.org/ome/ticket/12323

For some reason PanoJS has that off on Mac
```
// The dafault is to pan with wheel events on a mac and zoom on other systems
PanoJS.USE_WHEEL_FOR_ZOOM = (navigator.userAgent.indexOf("Mac OS X")>0 ? false: true);
```
I cannot find any explanations why, but this PR should unify it.