Merge pull request openlayers#363 from probins/projex2.12

Improve proj4js examples docs 2.12

Author: Éric Lemoine

examples/graticule.html

@@ -93,7 +93,7 @@
         <h1 id="title">Graticule Example</h1>
 
         <div id="tags">
-          graticule, grid
+          graticule, grid, projection, proj4js, reproject, transform
         </div>
 
         <p id="shortdesc">

examples/using-proj4js.html

@@ -64,7 +64,7 @@ <h1 id="title">Using Proj4JS for vector reprojection</h1>
             you would not inlude Proj4JS the way it is done in this example.
             In a production environment you would furthermore have a local copy 
             of the Proj4JS-projection definition that is hotlinked in this 
-            example.
+            example (see Graticule example for how to do this).
         </p>
         <div id="map">
         </div>