Api authorisation

Closes #63 
Also, do you know if the `find` will first return the results to node before skipping and limiting? Or does that happen at database level? (just from looking at the line one would assume the `find` is an immediate function call of course)

It would be cool to get the paging to work at database level, since all the results won't be pulled into memory...

@armageddon you might have some ideas?