feat: support IE9

[marclaval]

This PR adds support for IE9,. which doesn't require that many changes.
Some more details about what was needed to make the demo app to work and the full test suite to pass:

Source:

• Time picker: in IE9, a disabled <fieldset> doesn't disable children.

Demo:

• Added classList polyfill to the demo website.

Testing:

• Added Angular 2's testing polyfills to Karma's setup.
• Increased Karma's timers for slow IE9.

Spec:

• Pagination: in IE9, with the polyfill, classList need to be retrieved each time.
• Progress bar: no value attribute in IE9 (not sure why attribute was used).
• Radio group: some race condition was happening, making this test to fail. Note: it was occuring also in Chrome when focusing this particular test suite, but not when running the full campaign.
• Typeahead: IE9 requires a different way to fire events.

[maxokorokov]

Actually instead of adding classlist polyfill I would throw it away altogether and fix that one test with more usual expect(...).toHaveCssClass('...'). I think it was one of the first tests I wrote and forgot to fix that...

P.S. Ah, I see you need it for the demo too

[pkozlowski-opensource]

@maxokorokov I think that we need a polyfill for the core of Angular itself (ex. [class.foo] is using classList behind the scenes). But yes, we could / should change this test for sure.

[wesleycho]

Super minor, but probably should remove the spaces before : here

[marclaval]

Fixed