Get a directed edge given its index within the tile (do not need
entire graphid.
Outline of the A* algorithm. Still some missing pieces and cleanup
needed.
Add tests and get adjecency list working.
Merge remote-tracking branch 'origin/master' into dwn
Merge pull request #42 from mapzen/dwn

Adjacency List Updates
first pass at adding lua
added lua class
erge remote-tracking branch 'origin' into lua

Conflicts:
	src/mjolnir/pbfgraphbuilder/pbfgraphbuilder.cc
added LuaTagTransform class.  Added lua parsing logic.
removed pbfgraphbuilder
Merge pull request #43 from mapzen/lua

Lua
merge upstream and resolve conflicts