Fix punctuation in quotes, and quote signs

- period and comma inside quotes
- " to <quote>
- some " to <literal> when it is a var value

chapter02/hostreqs.xml

@@ -30,7 +30,7 @@
     modern Linux distributions. Also note that many distributions will
     place software headers into separate packages, often in the form of
     <quote>&lt;package-name&gt;-devel</quote> or
-    <quote>&lt;package-name&gt;-dev</quote>. Be sure to install those if
+    <quote>&lt;package-name&gt;-dev.</quote> Be sure to install those if
     your distribution provides them.</para>
 
    <para>Earlier versions of the listed software packages may work, but have

chapter02/mounting.xml

@@ -16,7 +16,7 @@
   <envar>LFS</envar> environment variable described in the previous section.
   </para>
   
-  <para>Strictly speaking, one cannot "mount a partition". One mounts the <emphasis>file
+  <para>Strictly speaking, one cannot "mount a partition." One mounts the <emphasis>file
   system</emphasis> embedded in that partition. But since a single partition can't contain
   more than one file system, people often speak of the partition and the
   associated file system as if they were one and the same.</para>

chapter02/stages.xml

@@ -69,7 +69,7 @@
 
       <listitem>
         <para>A few operations, from <quote>Changing Ownership</quote> to
-        <quote>Entering the Chroot Environment</quote>, must be done as the
+        <quote>Entering the Chroot Environment,</quote> must be done as the
         <systemitem class="username">root</systemitem> user, with the LFS
         environment variable set for the &root; user.</para>
       </listitem>