Convert from CSS to SCSS. Make a multitude of refinements to styling along the way.

Remove unused glade UI file. Added CSS classes to various components. Fix some alignment issues. Renamed our albums_strip to favorites_list.

Implement recursive file parsing in KotoIndexedAlbum with the intent of using it for "discs" / CD, useful for albums like Foo Fighters: In Your Honor that have 2 or more CDs. Still need to work on refining this further.

Add stub function in our album view for a planned separation of the track listing so we can do it based on discs and other depth-of-3 sub-folders.

theme/_button.scss

@@ -0,0 +1,5 @@
+.koto-button {
+	& > image {
+		margin-right: 10px;
+	}
+}