INT-2917 Doc: Add "Requirements" Chapter

Also addresses:

* INT-3128 Remove old SpringSource logo

INT-2917 Fix versions

INT-2917 Polishing

INT-2917 Fixed wording

src/reference/docbook/index.xml

@@ -8,18 +8,6 @@
     <productname>Spring Integration</productname>
     <releaseinfo>${version}</releaseinfo>
 
-    <!-- TODO: this isn't showing up. -->
-    <mediaobject>
-      <imageobject role="fo">
-        <imagedata fileref="images/logo.png"
-          format="PNG" align="center"/>
-      </imageobject>
-      <imageobject role="html">
-        <imagedata fileref="images/logo.png" format="PNG" align="center"/>
-      </imageobject>
-    </mediaobject>
-    <!-- END TODO -->
-
     <authorgroup>
       <author>
         <firstname>Mark</firstname>