add intial location and path location objects for correlating input locations to the graph network as input to the path generation algorithm. also add validity checks to latlng object. add a few minor tests, need more of these
Merge remote-tracking branch 'origin/kk_loki' into dwn
oops forgot to add pathlocation sources
Merge remote-tracking branch 'origin/kk_loki' into dwn
add location to path location initialization
Merge remote-tracking branch 'origin/master' into dwn
Merge remote-tracking branch 'origin/kk_loki' into dwn
Fix level (was passing in tilesize!).
Merge pull request #50 from mapzen/dwn

Fix hierarchy level.
Merge branch 'master' of https://github.com/mapzen/valhalla into gdg