[Patches] Preparation for tevent impersonation (part1)

[David Disseldorp]

Hi Metze,

On Thu, 14 Jun 2018 20:54:26 +0200, Stefan Metzmacher wrote:

> For async code we always have the 'state' variable to use for temporary
> memory, so we don't need talloc_stackframes...

Indeed, we just need to encourage people to use it instead of the
talloc_tos() context, and begin migrating over helper functions :)

Cheers, David