Merge branch 'master' into pgraster

Conflicts:
	npm-shrinkwrap.json
	package.json

config/environments/development.js.example

@@ -144,7 +144,8 @@ var config = {
         host: 'localhost',
         port: 6082,
         secret: 'xxx',
-        ttl: 86400
+        ttl: 86400,
+        layergroupTtl: 86400 // the max-age for cache-control header in layergroup responses
     }
     // If useProfiler is true every response will be served with an
     // X-Tiler-Profile header containing elapsed timing for various