Fix Open Sans font by moving it back to the top of the stylesheet

Also include a fallback to sans-serif
Builder: Display grid when grid/column features tabs are clicked
Fix links in dgrid builder header
Merge branch 'builder-0.4-styling' of github.com:kfranqueiro/dgrid into builder-0.4-styling

Signed-off-by: Torrey Rice <rice@sitepen.com>

Conflicts:
	builder/resources/builder.css