documentation/poky-ref-manual: Converted ref-classes to chapter

As part of moving the reference manual to a real reference manual I
am removing the "appendix" classification and having everthing be
a chapter.  I changed the "ref-classes" appendix to a chapter and
made sure any references in the doc set use the proper term now
(chapter).

(From yocto-docs rev: 54991c7fb0a2d3a894249f8a253b1a974cf2e571)

Signed-off-by: Scott Rifenbark <scott.m.rifenbark@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

documentation/poky-ref-manual/ref-classes.xml

@@ -1,9 +1,9 @@
-<!DOCTYPE appendix PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
+<!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
 "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"
 [<!ENTITY % poky SYSTEM "../poky.ent"> %poky; ] >
 
-<appendix id='ref-classes'>
-<title>Reference: Classes</title>
+<chapter id='ref-classes'>
+<title>Classes</title>
 
 <para>
     Class files are used to abstract common functionality and share it amongst multiple 
@@ -591,7 +591,7 @@
     <title>Other Classes</title>
 
     <para>
-        Thus far, this appendix has discussed only the most useful and important 
+        Thus far, this chapter has discussed only the most useful and important 
         classes.
         However, other classes exist within the <filename>meta/classes</filename> directory 
         in the <ulink url='&YOCTO_DOCS_DEV_URL;#source-directory'>source directory</ulink>.
@@ -669,7 +669,7 @@
 -->
 
 
-</appendix>
+</chapter>
 <!-- 
 vim: expandtab tw=80 ts=4 
 -->