Fastclick support, .l-nav updates

•  Included Fastclick.js for speedier clicks on mobile devices.

•  Added -ms- support for ::placeholder selector, and combined
::selection  to save some kb's ya'll.

•  Fixed .l-nav width on breakpoint(baby)

•  Removed li { line-height: auto; } because declaring defaults are
stupid.

•  Deleted .intro-text due to lack of use.

•  Deleted duplicates of strong, b, dt, em, i, and q selectors.

•  Updated media queries to be sexier.

•  Refined .l-nav's code. It was messy and made me sad.