Make meaningful direction names

[dkesh]

Presently, URLs for routes expose Capital Metro identifiers for route direction. Unfortunately, these identifiers are inconsistent. For example:

http://instabus.org/#/route/801/direction/1 is SB
http://instabus.org/#/route/1/direction/1 is NB

In both instances, flipping the final bit returns the reverse direction.

This presents two issues: 1) it is not obvious which direction a URL is for from looking at the URL.
2) Due to the inconsistencies in the CapMetro direction API, it is almost misleading; a reasonable person could believe that the direction bit is independent of the route.

Instead, instabus could use its own, meaningful identifiers for route direction. For example:

http://instabus.org/#/route/801/direction/N for NB
http://instabus.org/#/route/1/direction/S for SB