Added a Reserved Names page to the userguide, and migrated reserved controller names into it.

Added a Common Functions page to the userguide for globally available functions.
diff --git a/user_guide/general/urls.html b/user_guide/general/urls.html
index 9902083..8ba46e3 100644
--- a/user_guide/general/urls.html
+++ b/user_guide/general/urls.html
@@ -145,8 +145,7 @@
    ·  

 <a href="#top">Top of Page</a>&nbsp;&nbsp;&nbsp;&middot;&nbsp;&nbsp;

 <a href="../index.html">User Guide Home</a>&nbsp;&nbsp;&nbsp;&middot;&nbsp;&nbsp;

-Next Topic:&nbsp;&nbsp;<a href="controllers.html">Controllers</a>

-</p>

+Next Topic:&nbsp;&nbsp;<a href="reserved_names.html">Reserved Names</a></p>

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 </div>