r4547: - added talloc_new(ctx) macro that is a neater form of the common talloc(ctx...

r4547: - added talloc_new(ctx) macro that is a neater form of the common talloc(ctx, 0) call.

- cleaned up some talloc usage in various files

I'd like to get to the point that we have no calls to talloc(), at
which point we will rename talloc_p() to talloc(), to encourage
everyone to use the typesafe functions.
(This used to be commit e6c81d7c9f8a6938947d3c1c8a971a0d6d50b67a)