Idea for improving firebase elements

[kristianmandrup]

location="https://{{globals.firebase}}.firebaseio.com/... still seems like a rather "crude" approach

Since all firebase endpoints have this form, it still seems a bit superfluous. Would be better as location="{{globals.firebase.endpoint}}. Might as well extract it into a separate custom element more along: <firebase-model app="{{globals.firebase.account}} path="..." />`