De-overload configuration file parameter "standby_reconnect_timeout"

Currently the (very generic sounding) "standby_reconnect_timeout" configuration
file parameter is used in several different contexts and it would be useful
to have more granular control over the different timeouts it's used to configure.

This patch introduces "node_rejoin_timeout", used in place of "standby_reconnect_timeout"
(which wasn't documented) when "repmgr node rejoin" is executed, to determine
how long to wait for the node to rejoin the replication cluster.

Additionally "repmgrd_standby_startup_timeout" is introduced as a timeout for
failover situations, when repmgrd executes "repmgr standby follow" to follow
a new primary, and waits for the standby to restart and become available
for connections.

"standby_reconnect_timeout" is now only relevant for "repmgr standby switchover".

Implements GitHub #454.

doc/repmgr-node-rejoin.sgml

@@ -115,7 +115,24 @@
 
     </variablelist>
   </refsect1>
+ <refsect1>
+    <title>Configuration file settings</title>
 
+    <para>
+      <itemizedlist spacing="compact" mark="bullet">
+       <listitem>
+         <simpara>
+           <literal>node_rejoin_timeout</literal>:
+		   the maximum length of time (in seconds) to wait for
+		   the node to reconnect to the replication cluster (defaults to
+		   the value set in <literal>standby_reconnect_timeout</literal>,
+		   60 seconds).
+		 </simpara>
+	   </listitem>
+	  </itemizedlist>
+	</para>
+
+ </refsect1>
   <refsect1>
     <title>Event notifications</title>
     <para>

doc/repmgr-standby-switchover.sgml

@@ -154,8 +154,8 @@
        <listitem>
          <simpara>
            <literal>standby_reconnect_timeout</literal>:
-           Number of seconds to attempt to reconnect to the demoted primary
-           once it has been restarted.
+           number of seconds to attempt to wait for the demoted primary
+           to reconnect to the promoted primary (default: 60 seconds)
          </simpara>
        </listitem>