[PATCH] serf compile fixes

[Garrett Rooney]

So with the amount of change happening in serf, I imagine these 
problems have already been fixed in gstein or jerenkrantz's local 
tree's, but in case they haven't, here's a few compile fixes.

-garrett
* serf.h
  (serf_request_get_alloc): return a pointer to a serf_bucket_alloc_t, 
as
   you can't return the structure since it's only forward declared, and 
we
   only have a pointer anyway.

* context.c
  (serf_request_deliver): remove return, this function returns void.
  (serf_request_get_alloc): adjust for change to prototype.