Fix #1608: Show wiki page of alias consequent for Related Tags

Make related tags apply aliases before fetching tags from the wiki page.

app/logical/related_tag_query.rb

@@ -1,8 +1,8 @@
 class RelatedTagQuery
   attr_reader :query, :category
 
-  def initialize(query, category)
-    @query = query.strip
+  def initialize(query, category = nil)
+    @query = TagAlias.to_aliased(query.strip).join(" ")
     @category = category
   end
 

app/models/wiki_page.rb

@@ -250,7 +250,7 @@ class WikiPage < ActiveRecord::Base
       else
         match
       end
-    end.map {|x| x.mb_chars.downcase.tr(" ", "_").to_s}
+    end.map {|x| x.mb_chars.downcase.tr(" ", "_").to_s}.uniq
   end
 
   def visible?