remove spuriously committed files
separate LayoutItem and ComponentItem

This adds the fully sizing logic to ComponentItem
remove the absolute sizing logic

That functionality now lives on ComponentItem
cleanup
add reference to ComponentItem
move CSS images to css directory
remove unused css file
fix typo in max size computation
add import css module
update image urls
update sample page
add third party libs
more reliable hit testing for button release

this fixes an issue where the text span was the click target on the
PushButton subclass
target ES5 in the build
improve the API of TitleBar
add support for window content
add third party references
update Window CSS
update sample app with some window content
regenerate the output