tm: more details about processing doen by t_check_trans()

- note that last reply is resent for retransmissions matching a
  transaction

modules/tm/README

@@ -2479,9 +2479,11 @@ Note
        not needed for a statefull proxy and it requires additional memory,
        tm will not keep this information unless needed by some other
        module or callbacks).
-     * For other requests (non ACKs and non CANCELs), it will terminate
-       the script for retransmissions and return false for new requests
-       (for which no transaction exists yet).
+     * For other requests (non ACKs and non CANCELs), in case of a
+       retransmission matching a transaction, it resends the last reply
+       for that transaction and terminates the config execution.
+       Otherwise, it returns false (in case of new requests for which no
+       transaction exists yet).
 
 Note
 

modules/tm/doc/functions.xml

@@ -1381,9 +1381,11 @@ if (t_check_status("(487)|(408)")) {
 				</note>
 			</listitem>
 			<listitem>
-				<para>For other requests (non ACKs and non CANCELs), it will
-				terminate the script for retransmissions and return false for
-				new requests (for which no transaction exists yet).</para>
+				<para>For other requests (non ACKs and non CANCELs), in case of
+				a retransmission matching a transaction, it resends the last
+				reply for that transaction and terminates the config execution.
+				Otherwise, it returns false (in case of new requests for which
+				no transaction exists yet).</para>
 			</listitem>
 		</itemizedlist>
 	</para>