Allow NSH date command with no RTC. This command is useful without an RTC too. Also, this permits testing on the simulator which never has an RTC

Documentation/NuttShell.html

@@ -8,7 +8,7 @@
   <tr align="center" bgcolor="#e4e4e4">
     <td>
       <h1><big><font color="#3c34ec"><i>NuttShell (NSH)</i></font></big></h1>
-      <p>Last Updated: August 7, 2014</p>
+      <p>Last Updated: April 11, 2015</p>
     </td>
   </tr>
 </table>
@@ -1181,7 +1181,6 @@ date [-s &quot;MMM DD HH:MM:SS YYYY&quot;]
 <p>
   <b>Synopsis</b>.
   Show or set the current date and time.
-  This command is only supported if the platform supported RTC hardware (<code>CONFIG_RTC=y</code>).
 </p>
 <p>
   Only one format is used both on display and when setting the date/time:
@@ -2568,7 +2567,7 @@ nsh>
   </tr>
   <tr>
     <td><b><code>date</code></b></td>
-    <td><code>CONFIG_RTC</code></td>
+    <td><br></td>
     <td><code>CONFIG_NSH_DISABLE_DATE</code></td>
   </tr>
   <tr>