Add preview on save

and improve discoverability of command-enter feature :)

package.json

@@ -97,7 +97,7 @@
         "c9.ide.navigate": "#1fbb7cd53b",
         "c9.ide.newresource": "#981a408a7b",
         "c9.ide.openfiles": "#2ae85a9e33",
-        "c9.ide.preview": "#2acbe41e62",
+        "c9.ide.preview": "#407dfdb696",
         "c9.ide.preview.browser": "#04760484d1",
         "c9.ide.preview.markdown": "#bc846e1562",
         "c9.ide.pubsub": "#a85fb27eca",
@@ -108,7 +108,7 @@
         "c9.ide.run": "#1a5a660c44",
         "c9.ide.run.build": "#0598fff697",
         "c9.ide.run.debug.xdebug": "#9956689819",
-        "c9.ide.save": "#2de9fd7c2d",
+        "c9.ide.save": "#6007933698",
         "c9.ide.scm": "#ca3c94b84f",
         "c9.ide.terminal.monitor": "#1ccac33b0d",
         "c9.ide.test": "#a282ec1619",