Fix tag ordering in humanized_essential_tag_string.

* Pick the largest character or copyright tags by post count. Previously
  we picked the tags with the longest names, which was nonsensical.

* Remove tag cateogory logic from config file. We can't avoid hardcoding
  some knowledge about tag categories here, so there's no point in trying.

This affects tab titles on post show pages as well as filenames in
downloaded images.

app/models/tag.rb

@@ -218,46 +218,52 @@ class Tag < ApplicationRecord
     end
   end
 
-  module NameMethods
-    def normalize_name(name)
-      name.to_s.mb_chars.downcase.strip.tr(" ", "_").to_s
+  concerning :NameMethods do
+    def unqualified_name
+      name.gsub(/_\(.*\)\z/, "").tr("_", " ")
     end
 
-    def create_for_list(names)
-      names.map {|x| find_or_create_by_name(x).name}
-    end
-
-    def find_or_create_by_name(name, creator: CurrentUser.user)
-      name = normalize_name(name)
-      category = nil
-
-      if name =~ /\A(#{categories.regexp}):(.+)\Z/
-        category = $1
-        name = $2
+    class_methods do
+      def normalize_name(name)
+        name.to_s.mb_chars.downcase.strip.tr(" ", "_").to_s
       end
 
-      tag = find_by_name(name)
+      def create_for_list(names)
+        names.map {|x| find_or_create_by_name(x).name}
+      end
 
-      if tag
-        if category
-          category_id = categories.value_for(category)
+      def find_or_create_by_name(name, creator: CurrentUser.user)
+        name = normalize_name(name)
+        category = nil
 
-          # in case a category change hasn't propagated to this server yet,
-          # force an update the local cache. This may get overwritten in the
-          # next few lines if the category is changed.
-          tag.update_category_cache
-
-          if tag.editable_by?(creator)
-            tag.update(category: category_id)
-          end
+        if name =~ /\A(#{categories.regexp}):(.+)\Z/
+          category = $1
+          name = $2
         end
 
-        tag
-      else
-        Tag.new.tap do |t|
-          t.name = name
-          t.category = categories.value_for(category)
-          t.save
+        tag = find_by_name(name)
+
+        if tag
+          if category
+            category_id = categories.value_for(category)
+
+            # in case a category change hasn't propagated to this server yet,
+            # force an update the local cache. This may get overwritten in the
+            # next few lines if the category is changed.
+            tag.update_category_cache
+
+            if tag.editable_by?(creator)
+              tag.update(category: category_id)
+            end
+          end
+
+          tag
+        else
+          Tag.new.tap do |t|
+            t.name = name
+            t.category = categories.value_for(category)
+            t.save
+          end
         end
       end
     end
@@ -921,7 +927,6 @@ class Tag < ApplicationRecord
   include CountMethods
   include CategoryMethods
   extend StatisticsMethods
-  extend NameMethods
   extend ParseMethods
   extend SearchMethods
 end