issues with vdom siblings still remain. siblings will get clobbered if/when
the vdom updates. Still works well enough when the hpass element is the
first sibling

the value of `iconPass` is used to initialize an hpass vdom element
in eg the tabbar renderer

…ndling

accomplished this in part by moving a bunch of the complexity to the
creatDOMNode function

…ring

still need to figure out how to handle cleanup; current implementation likely
causes a memory leak due to uncleaned-up React components

…ully

still getting some unittest failures in FocusTracker and TabBar in Widgets