Fix #789470 Typos etc. in the system administration guide

system-admin-guide/C/lockdown-command-line.page

@@ -26,7 +26,8 @@
   <title>Disable command-line access</title>
 
   <p>You can prevent users from being able to access the command-line through
-  virtual terminals and terminal applications by in three areas:</p>
+  virtual terminals and terminal applications by following the steps described
+  below.</p>
 
   <list>
     <item>

system-admin-guide/C/lockdown-printing.page

@@ -66,7 +66,7 @@ disable-printing=true
       <listing>
         <title><file>/etc/dconf/db/local.db/locks/printing</file></title>
 <code>
-# Lock file saving settings
+# Lock printing settings
 /org/gnome/desktop/lockdown/disable-printing
 </code>
       </listing>

system-admin-guide/C/lockdown-repartitioning.page

@@ -58,8 +58,8 @@
       <listing>
 <code><![CDATA[
   <action id="org.freedesktop.udisks2.modify-device">
-     <description>Modify the disks settings</description>
-     <message>Authentication is required to modify the disks settings</message>
+     <description>Modify the drive settings</description>
+     <message>Authentication is required to modify drive settings</message>
     <defaults>
       <allow_any>no</allow_any>
       <allow_inactive>no</allow_inactive>
@@ -77,7 +77,6 @@
   </steps>
 
   <p>When the user tries to change the disk settings, the following message is
-  shown: <gui>Authentication is required to modify the disks
-  settings</gui>.</p>
+  shown: <gui>Authentication is required to modify drive settings</gui>.</p>
 
 </page>

system-admin-guide/C/network-printer-config.page

@@ -25,7 +25,7 @@
     <p>Adapted from GNOME Bugzilla – Bug 694569</p>
   </comment>
 
-  <p>This topic explains how to make printers, windows printers in particular,
+  <p>This topic explains how to make printers, Windows printers in particular,
   available in GNOME.</p>	
 
   <p>There is no preconfiguration needed for being able to install Samba 
@@ -46,11 +46,11 @@
       <gui>Unlock</gui> button.</p>
     </item>
     <item>
-      <p>Click the <key>+</key> key below the list of printers.</p>
+      <p>Click the <gui>+</gui> button below the list of printers.</p>
     </item>
     <item>
       <p>If your printers are public, wait for the printers which are 
-      available on your windows network to appear. Otherwise, type the address 
+      available on your Windows network to appear. Otherwise, type the address
       of the Samba server and press <key>Enter</key>.</p>
     </item>
     <item>
@@ -61,7 +61,7 @@
       <p>Select the printer to be installed.</p>
     </item>
     <item>
-      <p>Press the <key>Add</key> key.</p>
+      <p>Press the <gui>Add</gui> button.</p>
     </item>
     <item>
       <p>From the drivers available on your computer, select a suitable driver