Scrollable: in some conditions, the scrolling is broken on iOS 8

[AdrianVasiliu]

In some conditions, on iOS 8 (reproduced on 8.1, 8.1.1 and 8.2 beta, both iPhone and iPad), the scrolling using delite/Scrollable is broken. This is reproducible with the List (extending indirectly delite/Scrollable) used inside the popup of deliteful/Combobox. In other contexts (for instance with a scrollable List used directly in the page), the scrolling works in iOS 8 too...

How to reproduce: load for instance deliteful/samples/Combobox.html in Safari on iOS 8.x, touch a combo and try to scroll the content. (Depending on screen size, you may need to turn the device into landscape such that there is enough scrollable content.)

[AdrianVasiliu]

Fix pushed in 8f60451.

This CSS setting (now removed) is something I use for native scrolling since the time I starting prototyping it for dojox/mobile. As far as I remember it was recommended for iOS 5 and maybe some old Android, then I found it harmless and, to be on the safe side - in case it might still be useful for some browser - I kept it till now, and found it harmless in no situation except now with the Combobox on iOS 8.

Tested this fix for non-regression in iOS 7.1.2, 8.1.1, 8.2 beta, Android 4.4.4, 5 and 4.2.2 (chrome + stock browser).