Layer Categories window revamped

The Windows > Information > Layer Categories window now looks and feels like the Object Lister window.

New or changed functionality includes the following:

• You can now expand a category to view the layers that belong to it, by clicking the little arrow to the left of the category name.
• You can drag and drop layers from one category to another using the . You can also drag and drop layers from the Object Lister to the Layer Categories window in the same way.
• To make a category visible/invisible, click the category icon (instead of the "eye" icon in the old window).
• To make a specific layer visible/invisible, click its icon (small square).
• To pick a category or layer, click its name (instead of the "pick" icon in the old window).

  Holding or ( for Mac) works for additive selection.

• There is a Search & Pick box at the top of the window which works like the one in the Object Lister.