Improve button styles

 - Reorganize styles
 - Add colors for flat buttons
 - Add style for disabled buttons
 - Other minor improvements
Merge pull request #114 from npvn/button

Improve button styles
improved ripples.js
Improve styling for dialogs

- More padding
- Deeper shadow
- Add rounded corners
- A pull-left flat button can be added
added support for mobile devices to ripples.js
Merge pull request #118 from npvn/dialog

Improve styling for dialogs
Merge upstream/develop into card