Update NSH document, README, and comments in a script file

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: July 20, 2016</p>
+      <p>Last Updated: August 4, 2016</p>
     </td>
   </tr>
 </table>
@@ -3277,7 +3277,7 @@ nsh&gt;
   </tr>
   <tr>
     <td><b><code>mkfifo</code></b></td>
-    <td><code>CONFIG_NFILE_DESCRIPTORS</code> &gt; 0 &amp;&amp; <code>CONFIG_PIPES</code></td>
+    <td><code>CONFIG_NFILE_DESCRIPTORS</code> &gt; 0 &amp;&amp; <code>CONFIG_PIPES</code> &amp;&amp; <code>CONFIG_DEV_PIPE_SIZE</code> &gt; 0</td>
     <td><code>CONFIG_NSH_DISABLE_MKFIFO</code></td>
   </tr>
   <tr>

tools/README.txt

@@ -625,7 +625,6 @@ sethost.sh
       -32|64 selects 32- or 64-bit host (Only for Cygwin).  Default 64
       -h will show this help test and terminate
 
-
 refresh.sh
 ----------
 

tools/sethost.sh

@@ -212,7 +212,8 @@ cd $nuttx || { echo "ERROR: failed to cd to $nuttx"; exit 1; }
 make clean_context 1>/dev/null 2>&1
 make olddefconfig 1>/dev/null 2>&1
 
-# Restore any previous .config and Make.defs files
+# Move config file to correct location and restore any previous .config
+# and Make.defs files
 
 if [ "X$dotconfig" != "Xy" ]; then
   sed -i -e "s/^CONFIG_APPS_DIR/# CONFIG_APPS_DIR/g" .config