simplify SmoothScroller -- it is reimplementing Ink.Dom.Element functionality
add a check for external links in SmoothScroller, lest someone tries to click an external link with SmoothScroll
adding speed to per-element options
get rid of the double negative inherent to the name dontChangeHash
document SmoothScroller and its options
Merge branch 'develop' of github.com:sapo/Ink into develop