Add configuration parameter "repmgr_bindir"

This is to facilitate remote invocation of repmgr when the repmgr
binary is located somewhere other than the PostgreSQL binary directory, as it
cannot be assumed all package maintainers will install repmgr there.

This parameter is optional; if not set (the default), repmgr will fall back
to "pg_bindir" (if set).

Addresses GitHub #246.

configfile.h

@@ -75,6 +75,7 @@ typedef struct
 	char		data_directory[MAXPGPATH];
 	char		config_directory[MAXPGPATH];
 	char		pg_bindir[MAXPGPATH];
+	char		repmgr_bindir[MAXPGPATH];
 	int			replication_type;
 
 	/* log settings */
@@ -171,7 +172,7 @@ typedef struct
 
 #define T_CONFIGURATION_OPTIONS_INITIALIZER { \
 		/* node information */ \
-		UNKNOWN_NODE_ID, "", "", "", "", "", "", REPLICATION_TYPE_PHYSICAL,	\
+		UNKNOWN_NODE_ID, "", "", "", "", "", "", "", REPLICATION_TYPE_PHYSICAL,	\
 		/* log settings */ \
 		"", "", "", DEFAULT_LOG_STATUS_INTERVAL,	\
 		/* standby clone settings */ \