One ripple to rule them all.
Refactors buttons, FABs, radio buttons and checkboxes to all use the same ripples.
Also simplifies adding ripples to components by specifying the RippleEffect class (which is now required for checkboxes and radio buttons as well, which will otherwise not have ripples).
Fixes to animation demo:
- Moving demo further down the styleguide
- Code style fixes
Modifying animation demo so it works in IE.
Changes were needed because IE doesn't support calc() with CSS transitions.
Merge pull request #501 from sgomes/material-sprint-one-ripple

One ripple to rule them all.
Merge pull request #513 from sgomes/material-sprint-ie-animation-demo

Modifying animation demo so it works in IE.
Merge pull request #503 from sgomes/material-sprint-animation-fixes

Fixes to animation demo:
dropdown-menu prototype, item code
removed empty dropdown-menu.js
Merge pull request #515 from samthor/material-sprint

Add support for dropdown-menu and item components.
Completely rewrote sliders.
They now closely follow the Material Design spec, and work in Chrome, Safari, Firefox and IE>=10.
Fixing header panel demo in IE
Merge pull request #523 from sgomes/material-sprint-header-panel-ie

Fixing header panel demo in IE
Merge pull request #521 from sgomes/material-sprint-sliders

Completely rewrote sliders.