Additional and reorganized CSS for widget table layout

- Removed use of normalize.css, updated in bower.json and widget.html
- Reorganized sass partials
- Adding minimal css reset and base element to _base partial
- Adding `no-select` mixin to _helpers partial
- Defining some global colours to use in _variables partial
- Adding _table partial which defines the css for the table based layout of this widget
Merge pull request #38 from stulees/chore/table-css

Additional and reorganized CSS for widget table layout