Backport some EE helper changes

This backports some EE changes made to DropdownsHelper and
SelectsHelper. These changes can not easily be moved into an EE specific
module, as doing so would require reimplementing all modified methods.
Since there is no harm in including these changes in CE directly, we
just backport them.

app/helpers/dropdowns_helper.rb

@@ -11,6 +11,10 @@ module DropdownsHelper
 
       dropdown_output = dropdown_toggle(toggle_text, data_attr, options)
 
+      if options.key?(:toggle_link)
+        dropdown_output = dropdown_toggle_link(toggle_text, data_attr, options)
+      end
+
       dropdown_output << content_tag(:div, class: "dropdown-menu dropdown-select #{options[:dropdown_class] if options.key?(:dropdown_class)}") do
         output = []
 
@@ -49,6 +53,11 @@ module DropdownsHelper
     end
   end
 
+  def dropdown_toggle_link(toggle_text, data_attr, options = {})
+    output = content_tag(:a, toggle_text, class: "dropdown-toggle-text #{options[:toggle_class] if options.key?(:toggle_class)}", id: (options[:id] if options.key?(:id)), data: data_attr)
+    output.html_safe
+  end
+
   def dropdown_title(title, options: {})
     content_tag :div, class: "dropdown-title" do
       title_output = []

app/helpers/selects_helper.rb

@@ -29,6 +29,11 @@ module SelectsHelper
     classes = Array.wrap(opts[:class])
     classes << 'ajax-groups-select'
 
+    # EE requires this line to be present, but there is no easy way of injecting
+    # this into EE without causing merge conflicts. Given this line is very
+    # simple and not really EE specific on its own, we just include it in CE.
+    classes << 'multiselect' if opts[:multiple]
+
     opts[:class] = classes.join(' ')
 
     select2_tag(id, opts)