Removed "y" from iOS safari

safari on iOS does not yet fully support web forms 2.0. Invalid forms are submittable and datalist is not yet supported, so should be "a" not "y".
Added rangeslider.js as another polyfill
Merge pull request #522 from estelle/patch-1

Removed "y" from iOS safari
Merge pull request #524 from andreruffert/patch-1

Added rangeslider.js as another polyfill
data update