comments: move Javascript into component.

This is a minor breaking changing for userscripts that may have tried to
hook into our comment Javascript.

app/components/comment_component/comment_component.js

@@ -0,0 +1,34 @@
+class CommentComponent {
+  static initialize() {
+    if ($("#c-posts #a-show, #c-comments").length) {
+      $(document).on("click.danbooru.comment", ".edit_comment_link", CommentComponent.showEditForm);
+      $(document).on("click.danbooru.comment", ".expand-comment-response", CommentComponent.showNewCommentForm);
+      $(document).on("click.danbooru.comment", ".unhide-comment-link", CommentComponent.unhideComment);
+    }
+  }
+
+  static showNewCommentForm(e) {
+    $(e.target).hide();
+    var $form = $(e.target).closest("div.new-comment").find("form");
+    $form.show();
+    $form[0].scrollIntoView(false);
+    e.preventDefault();
+  }
+
+  static showEditForm(e) {
+    $(this).closest(".comment").find(".edit_comment").show();
+    e.preventDefault();
+  }
+
+  static unhideComment(e) {
+    let $comment = $(this).closest(".comment");
+    $comment.find(".unhide-comment-link").hide();
+    $comment.find(".body").show();
+    e.preventDefault();
+  }
+}
+
+
+$(document).ready(CommentComponent.initialize);
+
+export default CommentComponent;