AssetManager 0.5.5.55

Changes

Asset images are visible while editing an asset and can be removed explicitly.
Replacing an asset image removes the previous uploaded file.
Category images are displayed in the category table.
Column resizing is available centrally for regular application tables, with persistent widths per table and column.
Category table columns use stable storage keys for persistent widths.
Dashboard category images use contained scaling so images are not cropped in their preview frame.