Enable 3rd party vector tile sources

.gitignore

@@ -0,0 +1,6 @@
+.DS_Store
+_site
+.settings
+*.7z
+node_modules
+node.exe

lib/tilejson.js

@@ -211,8 +211,21 @@ TileJSON.prototype.get = function(url, callback) {
     var opts = {
         url: url,
         encoding: null,
+        //TODO: find a clean solution
+        //tell requestjs to *not* unzip, on the fly when fetching
+        //vetor tiles (*.pbf *.mvt), because all tile* modules
+        //expect gzipped buffers.
+        //let requestjs unzip all other requests, as gzipped responses
+        //break stuff further down the line.
+        gzip: !(url.indexOf('.pbf') > -1 || url.indexOf('.mvt') > -1),
         timeout: tilejson.timeout,
-        headers: {Connection: 'Keep-Alive'},
+        headers: {
+            Connection: 'Keep-Alive',
+            //always send gzip header, to enable 3rd party vector tile
+            //sources that gzip their response according to this header
+            //being present
+            'Accept-Encoding': 'gzip;q=1, identity;q=0'
+        },
         agent: url.indexOf('https:') === 0 ? httpsagent : agent
     };