Tab Ink Ripple UX Changes

[ThomasBurleson]

@see Polymer Tabs Demo

1. Color of the ripple should match the indicator and have opacity consistent with the spec.

The tab label text color is currently used.

2. Ink effects should sink into bar.

Was this deprecated feature?

[ajoslin]

Fixed #1.

I'm almost sure #2 was decided as not important in the last meeting.

If we do need to implement it, please reopen this issue.