dillon1000/react

Update root children using the appendChild/insertBefore/removeChild methods

This removes updateContainer and instead uses the regular child mutation
methods to insert into the root container and portals.

Since we're no longer clearing out the container DOM in updateContainer
we have to do that manually during initial mount. This now works on a
document and one of the tests end up unmounting the body when you render
into the document so I had to work around that bit since we don't yet
properly support rendering into the document root.