Styling additions to contact page

* style.css: Set body, page_wrap, content_wrap background color to
white.
* style.css: Add Lora font for '.content h1'.

* contact.jade: Mark required fields with red asterik.
* contact.jade: Introduce experimental rounded blue buttons.
* contact.jade: Use table & custom styling for office address and
phone, fax numbers.

* layout.jade: Remove font weights: 300 && 700. Add font weight 600.
* layout.jade: Disable table of contents navigational links.