Add Set method to PointLL (made Point2 Set method virtual).
Update format.
Added tiling of nodes. Calls GraphTileBuilder. Not actually writing
to file yet but the framework is working so far.
Add pbfgraphbuilder to gitignore.
Merge remote-tracking branch 'origin/master' into dwn
Back out pbfgraphbuilder until we get osm proto stuff in place.
Use initializer in constuctor.
Merge pull request #34 from mapzen/dwn

Add tiling to pbfgraphbuilder.