ref-manual, dev-manual: Completed first draft of 2.3 migration section.

(From yocto-docs rev: 42ab9e34da640b46d39741c9c83648dc65518ec1)

Signed-off-by: Scott Rifenbark <srifenbark@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

documentation/ref-manual/ref-classes.xml

@@ -1755,6 +1755,9 @@
                 <link linkend='qa-issue-textrel'><filename>ELF binary</filename></link>
                 message for more information regarding runtime performance issues.
                 </para></listitem>
+<!--
+This check was removed for YP 2.3 release
+
             <listitem><para><emphasis><filename>unsafe-references-in-binaries:</filename></emphasis>
                 Reports when a binary installed in
                 <filename>${base_libdir}</filename>,
@@ -1776,6 +1779,7 @@
                     <filename>/usr</filename>.
                 </note>
                 </para></listitem>
+-->
             <listitem><para><emphasis><filename>unsafe-references-in-scripts:</filename></emphasis>
                 Reports when a script file installed in
                 <filename>${base_libdir}</filename>,
@@ -3671,6 +3675,14 @@
         For an example, see the
         <filename>meta/conf/distro/include/yocto-uninative.inc</filename>.
     </para>
+
+    <para>
+        The <filename>uninative</filename> class is also used unconditionally
+        by the extensible SDK.
+        When building the extensible SDK,
+        <filename>uninative-tarball</filename> is built and the resulting
+        tarball is included within the SDK.
+    </para>
 </section>
 
 <section id='ref-classes-update-alternatives'>