Remove single alias/implication requests.

* Remove the single alias and implication request forms. From now
  on, bulk update requests are the only way to request aliases or
  implications.

* Remove the forum topic ID field from the bulk update request form.
  Instead, to attach a BUR to an existing topic you go to the topic then
  you click "Request alias/implication" at the top of the page.

* Update the bulk update request form to give better examples for the
  script format and to explain the difference between aliases and
  implications.

test/functional/tag_alias_requests_controller_test.rb

@@ -1,25 +0,0 @@
-require 'test_helper'
-
-class TagAliasRequestsControllerTest < ActionDispatch::IntegrationTest
-  context "The tag alias request controller" do
-    setup do
-      @user = create(:user)
-    end
-
-    context "new action" do
-      should "render" do
-        get_auth new_tag_alias_request_path, @user
-        assert_response :success
-      end
-    end
-
-    context "create action" do
-      should "render" do
-        assert_difference("ForumTopic.count", 1) do
-          post_auth tag_alias_request_path, @user, params: {:tag_alias_request => {:antecedent_name => "aaa", :consequent_name => "bbb", :reason => "ccc", :skip_secondary_validations => true}}
-        end
-        assert_redirected_to(forum_topic_path(ForumTopic.last))
-      end
-    end
-  end
-end

test/functional/tag_implication_requests_controller_test.rb

@@ -1,43 +0,0 @@
-require 'test_helper'
-
-class TagImplicationRequestsControllerTest < ActionDispatch::IntegrationTest
-  context "The tag implication request controller" do
-    setup do
-      travel_to(1.month.ago) do
-        @user = create(:user)
-      end
-    end
-
-    context "new action" do
-      should "render" do
-        get_auth new_tag_implication_request_path, @user
-        assert_response :success
-      end
-    end
-
-    context "create action" do
-      should "create forum post" do
-        assert_difference("ForumTopic.count", 1) do
-          post_auth tag_implication_request_path, @user, params: {:tag_implication_request => {:antecedent_name => "aaa", :consequent_name => "bbb", :reason => "ccc", :skip_secondary_validations => true}}
-        end
-        assert_redirected_to(forum_topic_path(ForumTopic.last))
-      end
-
-      should "create a pending implication" do
-        params = {
-          :tag_implication_request => {
-            :antecedent_name => "foo",
-            :consequent_name => "bar",
-            :reason => "blah blah",
-            :skip_secondary_validations => true
-          }
-        }
-
-        assert_difference("ForumTopic.count") do
-          post_auth tag_implication_request_path, @user, params: params
-        end
-        assert_redirected_to(forum_topic_path(ForumTopic.last))
-      end
-    end
-  end
-end