Update mouse wheel plugin to 3.1.6
Use event.deltaFactor of mousewheel plugin or fallback to the settings.mouseWheelSpeed
Merge pull request #258 from brandonaaron/mousewheel

Update mouse wheel plugin to 3.1.6
Merge pull request #259 from brandonaaron/deltaFactor

mousewheel deltaFactor
Updated release notes and documentation to match changes in mousewheel plugin