dev-manual, sdk-manual: Applied review comments for SDK movement

I applied several nits across the manuals based on reviewer
comments.  All these corrections relate to the task of shuffling
topics around that have to do with the extensible SDK and the
devtool.

(From yocto-docs rev: 9f8079adc7fa2897fd885aff8e64f9721212e9c7)

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

documentation/dev-manual/dev-manual-model.xml

@@ -1239,14 +1239,6 @@
                             Any changes you want to turn into patches must be
                             committed to the Git repository in the source tree.
                         </note></para>
-
-                        <para>Because there is no need to move the recipe,
-                        <filename>devtool finish</filename> either updates the
-                        original recipe in the original layer or the command
-                        creates a <filename>.bbappend</filename> in a different
-                        layer as provided by <replaceable>layer</replaceable>.
-                        </para>
-
                         <para>As a final process of the
                         <filename>devtool finish</filename> command, the state
                         of the standard layers and the upstream source is

documentation/sdk-manual/sdk-extensible.xml

@@ -26,8 +26,8 @@
 
     <para>
         In addition to the functionality available through
-        <filename>devtool</filename>, you can alternatively make use of
-        the toolchain directly to work on Makefile, Autotools, and
+        <filename>devtool</filename>, you can alternatively make use of the
+        toolchain directly, for example from Makefile, Autotools, and
         Eclipse-based projects.
         See the
         "<link linkend='sdk-working-projects'>Using the SDK Toolchain Directly</link>"
@@ -244,10 +244,6 @@
             number of sub-commands for each function.
             You can run <filename>devtool --help</filename> to see all the
             commands.
-            See the
-            "<ulink url='&YOCTO_DOCS_REF_URL;#ref-devtool-reference'><filename>devtool</filename>&nbsp;Quick Reference</ulink>"
-            in the Yocto Project Reference Manual for a
-            <filename>devtool</filename> quick reference.
         </para>
 
         <para>
@@ -285,8 +281,9 @@
 
         <para>
             The remainder of this section presents the
-            <filename>devtool add</filename> and
-            <filename>devtool modify</filename> workflows.
+            <filename>devtool add</filename>,
+            <filename>devtool modify</filename>, and
+            <filename>devtool upgrade</filename> workflows.
         </para>
 
         <section id='sdk-use-devtool-to-add-an-application'>
@@ -874,12 +871,6 @@
                             Any changes you want to turn into patches must be
                             committed to the Git repository in the source tree.
                         </note></para>
-                        <para>Because there is no need to move the recipe,
-                        <filename>devtool finish</filename> either updates the
-                        original recipe in the original layer or the command
-                        creates a <filename>.bbappend</filename> in a different
-                        layer as provided by <replaceable>layer</replaceable>.
-                        </para>
                         <para>As a final process of the
                         <filename>devtool finish</filename> command, the state
                         of the standard layers and the upstream source is