matching the directory structure btw src/ and test/unit/
transclude-footer should be the last directive applied, so that the dom prepared by other directives is ready for the vertical-fill-layout resizing.
registering the resize callback function in the controller prepares vertical-fill-layout for handling both cases where transclude-footer may be in a sibling or child scope
extending angular's jqlite prototype with a  function that supports the same amount of css selector syntax as the  and  extensions
restricting the search for the transclude mount points to child elements only, so it doesn't pick up nested <vertical-fill-layout> elements, and to save time traversing the dom
supporting nested vfl directives, and supporting an angular linker that wants to link the transclude-footer before the transclude-header