This change also means that the application actually starts after
the `noConflict` calls have erased any trace of Annotator or jQuery
from the global object.

AnnotationSync was using $.extend. Since I don't want to depend on
jQuery in the widget application indefinitely and I don't want to
depend on Annotator either there is not a single place to get this
function that works in both environments. Instead, a single purpose
module from NPM for extend is pulled in. Small modules FTW.