Avoid "dataset" in dom data getter and setter

[mattsahr]

Internet Explorer 10 and below can't use "dataset" to access data on a DOM element. Here's a fix for the mdlComponentHandler.js file.

ORIGINAL

var upgrades = component.element_.dataset.upgraded.split(',');
var componentPlace = upgrades.indexOf(
    component[componentConfigProperty_].classAsString);
upgrades.splice(componentPlace, 1);
component.element_.dataset.upgraded = upgrades.join(',');

UPDATED

var upgrades = component.element_.getAttribute("data-upgraded").split(',');
var componentPlace = upgrades.indexOf(
    component[componentConfigProperty_].classAsString);
upgrades.splice(componentPlace, 1);
component.element_.setAttribute("data-upgraded", upgrades.join(','));

[surma]

Confirmed. IE10 does not support dataset.

[Garbee]

Whoops, we also have problems in the component handler then... thanks for pointing this out.

[Garbee]

Oh, I think Surma may have mis-tagged this... I have patch for the problem in with PR #1190.

[surma]

My bad. Brain lag.