dev-manual, ref-manual, yocto-project-qs: Debian support added

Fixes [YOCTO #4912]

Throughout the manual set, various areas talk about the Linux
distributions we support and the required packages among other
items that are tied to a distro.  Debian had been missing except
from the list in the ref-manual that shows the releases we test
against.

I have attended to all areas where Debian needs to be mentioned
now.

Reported-by: Laszlo Papp <lpapp@kde.org>
(From yocto-docs rev: 2004567821add745d320106b0dc6cccb4f73b605)

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

documentation/ref-manual/introduction.xml

@@ -141,8 +141,8 @@
                 <listitem><para>Fedora release 18 (Spherical Cow)</para></listitem>
                 <listitem><para>CentOS release 6.3 (Final)</para></listitem>
                 <listitem><para>CentOS release 6.4 (Final)</para></listitem>
-                <listitem><para>Debian GNU/Linux 6.0 (squeeze)</para></listitem>
-                <listitem><para>Debian GNU/Linux 7.0</para></listitem>
+                <listitem><para>Debian GNU/Linux 6.0 (Squeeze)</para></listitem>
+                <listitem><para>Debian GNU/Linux 7.0 (Wheezy)</para></listitem>
                 <listitem><para>openSUSE 12.2</para></listitem>
                 <listitem><para>openSUSE 12.3</para></listitem>
             </itemizedlist>
@@ -172,11 +172,11 @@
         </para>
 
         <section id='ubuntu-packages'>
-            <title>Ubuntu</title>
+            <title>Ubuntu and Debian</title>
 
             <para>
                 The following list shows the required packages by function
-                given a supported Ubuntu Linux distribution:
+                given a supported Ubuntu or Debian Linux distribution:
                 <itemizedlist>
                     <listitem><para><emphasis>Essentials:</emphasis>
                         Packages needed to build an image on a headless