Began converting classes to new naming convention

- Converted hyphens to underscores for majority of class names.

- Tabs now use tab_modifier.

- Grids now use grid_

- Responsive helpers use %size_helper

- Removed excessive nesting in tab styling and added a clear fix to
allow for complex layouts inside tabs.

- Added spacing helpers (currently as silent classes).

- Removed excessive $type- variable names.

-Updated Normalize to 3.0.