OPC design change: Huge change, see description.

Bring First Name and Last Name, City and State, DOB and Gender side by side.
Reduce font-size of labels and inputs.
Change background color, border size, radius and color.
Responsiveness for the four column layout.
Merge branch 'hitesh/features/general'

Conflicts:
	skin/frontend/happy/default/css/happy_checkout.css