Revert "There are certain situations in which getAuth() may want to be overridden by a
backend for performance reasons. The attached patch converts getAuth() into a
virtual backend function. The default is for no change in functionality. In my
tests this leads to very significant performance improvements under certain
situations"

This reverts commit 8208210a367e200f5f16463e83c208a28ddc24c0.

Conflicts:
	pdns/packethandler.cc
don't use 'new' getAuth() in webserver