Layout/LayoutPanel components based on Yahoo Nesting Grids.

Layout is a wrapper component which should consist of layouts panels. Every layout panel could be positioned inside the layout with corresponding position attribute(with top, bottom, left, right and center values).

Currently for a horizontally aligned panels the "width" attribute means a part of outer panel what that component takes. This is a same semantic as HTML elements have - see HTML MultiLength In future we plan to expand the layouts with possibility of fixed and percents based width definitions.