Extract active header link method

Also changes how the active-ness is determined, from using the
controller name, to looking at the current url.
Add rules page

Includes minimal styles that attempt to make the amount of text a bit
more palatable. I think there's an opportunity for a much more cleaner
design, possibly with a layout similar to the getting started page. It'd
be great if someone volunteered to implement such a design!
Add ride validation to restrict to past 2 weeks
Add date restriction message to commute form
Fix padding for datepicker form element
Update welcome message for 2014 competition
Update countdown text style

The new title pushes the countdown further into the snowy mountain top
on my laptop screen. Adding the same the text shadow as the numbers, but
a bit smaller, to make it stand out.
Merge branch 'rules'
Merge branch '2014-title-change'
Merge branch 'commute-logging-restriction'