Implement Playlist functionality. My god...

Too many changes to summarize.

- Fixes #2.
- Fixes #3.
- Fixes #5.
- Fixes #7.

Start work on uncrustify config.

src/koto-dialog-container.h

@@ -0,0 +1,42 @@
+/* koto-dialog-container.h
+ *
+ * Copyright 2021 Joshua Strobl
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * 	http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+#include <glib-2.0/glib-object.h>
+#include <gtk-4.0/gtk/gtk.h>
+
+G_BEGIN_DECLS
+
+/**
+ * Type Definition
+**/
+
+#define KOTO_TYPE_DIALOG_CONTAINER koto_dialog_container_get_type()
+G_DECLARE_FINAL_TYPE(KotoDialogContainer, koto_dialog_container, KOTO, DIALOG_CONTAINER, GtkBox);
+#define KOTO_IS_DIALOG_CONTAINER(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj), KOTO_TYPE_DIALOG_CONTAINER))
+
+/**
+ * Functions
+**/
+
+KotoDialogContainer* koto_dialog_container_new();
+void koto_dialog_container_add_dialog(KotoDialogContainer *self, gchar *dialog_name, GtkWidget *dialog);
+void koto_dialog_container_handle_close_click(GtkGestureClick *gesture, int n_press, double x, double y, gpointer user_data);
+void koto_dialog_container_hide(KotoDialogContainer *self);
+void koto_dialog_container_show_dialog(KotoDialogContainer *self, gchar *dialog_name);
+
+G_END_DECLS