Revert "Replace quadratic emote list impl with Map"

This reverts commit 0f9bc44925.

The original commit was not backwards compatible with use cases that
users were relying on, such as emotes being sorted in insertion order by
default.

I will develop a new patch which fixes the performance issue in a
backwards compatible way.

templates/channel.pug

@@ -189,6 +189,11 @@ html(lang="en")
           .modal-body
             .pull-left
               input.emotelist-search.form-control(type="text", placeholder="Search")
+            .pull-right
+              .checkbox
+                label
+                  input.emotelist-alphabetical(type="checkbox")
+                  | Sort alphabetically
             .emotelist-paginator-container
             table.emotelist-table
               tbody

templates/channeloptions.pug

@@ -197,6 +197,11 @@ mixin emotes
     form.form-inline
       .form-group
         input.emotelist-search.form-control(type="text", placeholder="Search")
+      .form-group
+        .checkbox
+          label
+            input.emotelist-alphabetical(type="checkbox")
+            | Sort alphabetically
     .emotelist-paginator-container
     table.emotelist-table.table.table-striped.table-condensed
       thead