Add help about "Save & Close" Dependencies dlg button

Fixes #14

Author: delphidabbler

Src/Help/HTML/dlg_dependencies.htm

@@ -29,12 +29,18 @@ <h1>
     <p>
       This dialogue box is displayed by choosing the <em>View |
       Dependencies</em> menu item or by pressing
-      <span class="smallcaps">Ctrl+D</span>. It has two tabs:
-      <em>Depends Upon</em> and <em>Required By</em>.
+      <span class="smallcaps">Ctrl+D</span>.
     </p>
     <h2>
-      <em>Depends Upon</em> Tab
+      Tabs
     </h2>
+    <p>
+      The dialogue box has two tabs: <em>Depends Upon</em> and <em>Required
+      By</em>.
+    </p>
+    <h3>
+      <em>Depends Upon</em> Tab
+    </h3>
     <p>
       If the selected snippet has dependencies (i.e. snippets it depends upon in
       order to compile) a tree of snippets is displayed that shows the direct
@@ -47,13 +53,27 @@ <h2>
       error message is displayed. Such a dependency indicates there is an error
       in the database.
     </p>
-    <h2>
+    <h3>
       <em>Required By</em> Tab
-    </h2>
+    </h3>
     <p>
       This tab displays a simple list of snippets that immediately depend on the
       selected snippet. Again, if there are no snippets to list, a message is
       displayed to that effect.
     </p>
+    <h2>
+      <em>Select &amp; Close</em> button
+    </h2>
+    <p>
+      This button appears to the left of the <em>Close</em> and <em>Help</em>
+      buttons. It's purpose is to select the snippets listed on the currently
+      active tab and to display that selection when the dialogue box is closed.
+      If the active tab lists no snippets then the button is disabled.
+    </p>
+    <p>
+      <strong class="warning">Warning:</strong> Any selection made using this
+      button will replace any search results that were previously displayed. No
+      warning will be displayed.
+    </p>
   </body>
 </html>