I'm trying to produce my own skin for the first time and I'm spending a lot of time trying to work out things that are probably really basic, such as the different classes of layout, containers and widgets. Is this information recorded somewhere or could someone give me a quick lowdown on what the main ones mean? For instance how is a horizontal_adaptive_container different to a vertical one and what exactly does stick_to_sides_attachment mean and what other options are there that can be used?