Watcher should track newly created files

Currently newly created are added to the graph but not added the
watcher.

Fixes sass#1891

Author: xzyfer

Diff for: bin/node-sass

@@ -257,37 +257,36 @@ function watch(options, emitter) {
   gaze.add(watch);
   gaze.on('error', emitter.emit.bind(emitter, 'error'));
 
-  gaze.on('changed', function(file) {
-    var files = [file];
+  gaze.on('changed', updateWatcher);
+  gaze.on('added', updateWatcher);
 
-    // descendents may be added, so we need a new graph
+  gaze.on('deleted', function() {
     graph = buildGraph(options);
-    graph.visitAncestors(file, function(parent) {
-      files.push(parent);
-    });
-
-    // Add children to watcher
-    graph.visitDescendents(file, function(child) {
-      if (watch.indexOf(child) === -1) {
-        watch.push(child);
-        gaze.add(child);
-      }
-    });
-    files.forEach(function(file) {
-      if (path.basename(file)[0] !== '_') {
-        renderFile(file, options, emitter);
-      }
-    });
   });
+}
 
-  gaze.on('added', function() {
-    graph = buildGraph(options);
+function updateWatcher(file) {
+  var files = [file];
+
+  // descendents may be added, so we need a new graph
+  graph = buildGraph(options);
+  graph.visitAncestors(file, function(parent) {
+    files.push(parent);
   });
 
-  gaze.on('deleted', function() {
-    graph = buildGraph(options);
+  // Add children to watcher
+  graph.visitDescendents(file, function(child) {
+    if (watch.indexOf(child) === -1) {
+      watch.push(child);
+      gaze.add(child);
+    }
   });
-}
+  files.forEach(function(file) {
+    if (path.basename(file)[0] !== '_') {
+      renderFile(file, options, emitter);
+    }
+  });
+};
 
 /**
  * Run