Add missing post_control template and configuration values for thread merge functionality

inc/config.php

@@ -1441,6 +1441,7 @@
 	$config['mod']['link_bumpunlock'] = '[-Sage]';
 	$config['mod']['link_editpost'] = '[Edit]';
 	$config['mod']['link_move'] = '[Move]';
+	$config['mod']['link_merge'] = '[Merge]';
 	$config['mod']['link_cycle'] = '[Cycle]';
 	$config['mod']['link_uncycle'] = '[-Cycle]';
 
@@ -1610,6 +1611,8 @@
 	$config['mod']['editpost'] = ADMIN;
 	// "Move" a thread to another board (EXPERIMENTAL; has some known bugs)
 	$config['mod']['move'] = DISABLED;
+	// "Merge" a thread to same board or another board
+	$config['mod']['merge'] = MOD;
 	// Bypass "field_disable_*" (forced anonymity, etc.)
 	$config['mod']['bypass_field_disable'] = MOD;
 	// Post bypass unoriginal content check on robot-enabled boards
@@ -1977,7 +1980,7 @@
 	// Whether to append domain names to IP cloaks
 	$config['ipcrypt_dns'] = false;
 
-	// Enable auto IP note generation of deleted posts
+	// Enable auto IP note generation of moderator deleted posts
 	$config['autotagging'] = false;
 
 	// Enable PDF file thumbnail generation

templates/post/post_controls.html

@@ -51,6 +51,9 @@
 		<a title="{% trans %}Move reply to another board{% endtrans %}" href="?/{{ board.dir }}move_reply/{{ post.id }}">{{ config.mod.link_move }}</a>&nbsp;
 	{% endif %}
 {% endif %}
+{% if mod|hasPermission(config.mod.merge, board.uri) %}
+		<a title="{% trans %}Merge thread with another thread {% endtrans %}" href="?/{{ board.dir }}merge/{{ post.id }}">{{ config.mod.link_merge }}</a>&nbsp;
+{% endif %}
 {% if mod|hasPermission(config.mod.cycle, board.uri) %}
 	{% if post.cycle %}
 	<a title="{% trans %}Make thread not cycle{% endtrans %}" href="?/{{ secure_link(board.dir ~ 'uncycle/' ~ post.id) }}">{{ config.mod.link_uncycle }}</a>&nbsp;