[CLEANUP] move the session-related functions to session.c

proto_http.c was not suitable for session-related processing, it was
just convenient for the tranformation.

Some more splitting must occur: process_request/response in proto_http.c
must be split again per protocol, and the caller must run a list.

Some functions should be directly attached to the session or the buffer
(eg: perform_http_redirect, return_srv_error, http_sess_log).
diff --git a/include/proto/proto_http.h b/include/proto/proto_http.h
index 17f302d..0fcbea6 100644
--- a/include/proto/proto_http.h
+++ b/include/proto/proto_http.h
@@ -3,7 +3,7 @@
   This file contains HTTP protocol definitions.
 
   Copyright (C) 2000-2008 Willy Tarreau - w@1wt.eu
-  
+
   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation, version 2.1
@@ -87,6 +87,9 @@
 int http_find_header2(const char *name, int len,
 		      const char *sol, struct hdr_idx *idx,
 		      struct hdr_ctx *ctx);
+void http_sess_log(struct session *s);
+void perform_http_redirect(struct session *s, struct stream_interface *si);
+void return_srv_error(struct session *s, int err_type);
 
 #endif /* _PROTO_PROTO_HTTP_H */