Fix demos for 2.0-preview

[myfrom]

Demos doesn't work on 2.0-preview

There are few things to make them work again:

• Change <style is="custom-style"> to <custom-style><style is="custom-style"></style></custom-style> (Hybrid syntax valid for 2.0 and 1.0)
• Change <template is="dom-bind"> to <dom-bind><template is="dom-bind"></template></dom-bind> (Hybrid syntax valid for 2.0 and 1.0)
• Import <link rel="import" href="../../polymer/lib/elements/dom-bind.html"> to load dom-bind (required in 2.0)
• Change @apply mixins to new syntax @apply(--mixin); => @apply --mixin;

[michael-learns]

I've made the changes in the iron-swipeable-pages.html. It's not working though. @myfrom