Simplified JS example on frontpage

I suggest to remove error handling and logging. This example should get the basic idea across, not distract with production bloat.

_layouts/01_splash.html

@@ -125,22 +125,15 @@ <h2 class="med-news"><a href="{{site.baseurl}}{{ post1-url }}"> {{ post1-title }
 {% highlight js %}
 var mapnik = require("mapnik");
 var fs = require("fs");
-// register fonts and datasource plugins
 mapnik.register_default_fonts();
 mapnik.register_default_input_plugins();
 var map = new mapnik.Map(256, 256);
-map.load("./test/stylesheet.xml", function(err,map) {
-    if (err) throw err;
+map.load("./test/stylesheet.xml", function(err, map) {
     map.zoomAll();
     var im = new mapnik.Image(256, 256);
-    map.render(im, function(err,im) {
-        if (err) throw err;
-        im.encode("png", function(err,buffer) {
-            if (err) throw err;
-            fs.writeFile("map.png",buffer, function(err) {
-                if (err) throw err;
-                console.log("saved map image to map.png");
-            });
+    map.render(im, function(err, im) {
+        im.encode("png", function(err, buffer) {
+            fs.writeFile("map.png", buffer);
          });
     });
 });