Change data-key for options associated with element

To prevent conflicts with other plugins and jQuery features, the
data-key was renamed from 'options' to 'sliderOptions'
Update documentation

Add touch feature to documentation
Change error message for missing methods on plugin
Update link styles
Add feature 'destroy' to fully remove the slider

The public method 'destroy' removes all of the DOM changes, event
bindings, data associations and restores all elements and attributes to
the state before initialization of the element as slider.
Add responsive width for feature flexitems
Merge 'master' into branch