* Use "lib" in tsconfigs instead of "target".
Only add "dom" to libraries that need it. This is determined by a script, so many libraries that have "dom" maybe should not.
* Update new-package and readme
* Add back "target" where necessary
Removes refernces to the test backend from the html5 backend tests -
the two backends are distinct so it doesn't make sense to test one
inside the other