update to node-mapnik 1.3.x - refs mapnik/node-mapnik#209
bump package.json
use node-mapnik@1.3.0-alpha2
node-mapnik@1.3.0-alpha3
npm publish is borked, switch to github
bump to node-mapnik@1.3.0-alpha4
Reimplement backend in the modern age : )
Merge branch 'node-mapnik-1.3' into backend2

Conflicts:
	index.js
Update to mapnik 1.3
use node-mapnik@1.3.0
Merge pull request #32 from mapbox/node-mapnik-1.3

Update to node-mapnik 1.3.x - refs mapnik/node-mapnik#209
Add thin (sync) interface for wrapping sources as backends.
Merge branch 'master' into backend2
Merge pull request #35 from mapbox/backend2

Backend
0.5.0
Start tests for backend source. Refs #34.
Allow upstream backend to itself pass a mapnik vectortile object.
use node-mapnik@1.3.1
vtile.toJSON() needs to come after vt.parse() to return correct data
try parsing in backend