Vector tile support

Added ability to produce mapbox vector tiles when the .pbf extension is supplied. Added Mapbox GL JS example showcasing rendering vector tiles.

0.1.8

Update grainstore to 1.6.4 (highest node 4.x supported) in order to support mapnik 3.0.x styles.

Mapnik XML File support

Added Mapnik XML File support

0.1.5-node0.12

All new features applied to 0.1.5 but working with node 0.12

0.1.5

Node v4 not fully supported yet

Node 4.4

Update to node v4.4.5

Using node-Mapnik 3.5.13 and an updated windows mssql plugin. Image
comparsion tests brought back and http asset dropped in favor of
http-asset by mapbox

0.1.3

Fix 304 causes error

304 cause error where would try to check headers when they were
undefined.

0.1.2

Table bug fix and wrap sql only when needed

Conditionally wrap sql into subqueries if its not already. Drop default
sql table support

0.1.1

Multi-layer support. Drop use of table parameter

0.1.0

Express 4 and separate out express modules (possible breaking changes)