Merge Christpher Lam's 'trep-invoice' into stable.

Author: jralls

C/manual/ch_Reports.docbook

@@ -596,6 +596,12 @@
                   </para>
                 </listitem>
 
+                <listitem>
+                  <para><guilabel>Invoice</guilabel> is the associated
+                    invoice posted by, or settled by the transaction.
+                  </para>
+                </listitem>
+
                 <listitem>
                   <para><guilabel>Notes</guilabel>: Display the notes if the memo is unavailable
                   </para>