Add missing semicolons
Customizable slicePath and sliceTransform functions, close #1
New wheelnav and navItem properties: slicePathCustom, sliceSelectedPathCustom, sliceHoverPathCustom, sliceTransformCustom, sliceSelectedTransformCustom, sliceHoverTransformCustom
Add custom parameter to slicePath and sliceTransform functions
New wheelnav properties: selectedNavItemIndex, navItemCountLabeled, navItemCountLabelOffset