NetworkPkg: Use the New Functions from HttpLib

After submitting changes for HttpLib, other modules should be able to use
those functions
1 remove the private function and their calls
2 update it with the functions from httpLib

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ghazi Belaam <Ghazi.belaam@hpe.com>
Reviewed-by: Fu Siyuan <siyuan.fu@intel.com>
Reviewed-by: Samer EL-Haj-Mahmoud <elhaj@hpe.com>
Reviewed-by: Jiaxin Wu <jiaxin.wu@intel.com>

NetworkPkg/HttpDxe/HttpProto.h

@@ -2,6 +2,7 @@
   The header files of miscellaneous routines for HttpDxe driver.
 
 Copyright (c) 2015 - 2016, Intel Corporation. All rights reserved.<BR>
+(C) Copyright 2016 Hewlett Packard Enterprise Development LP<BR>
 This program and the accompanying materials
 are licensed and made available under the terms and conditions of the BSD License
 which accompanies this distribution.  The full text of the license may be found at
@@ -398,20 +399,6 @@ HttpTransmitTcp (
   IN  UINTN            TxStringLen
   );
 
-/**
-  Translate the status code in HTTP message to EFI_HTTP_STATUS_CODE defined 
-  in UEFI 2.5 specification.
-
-  @param[in]  StatusCode         The status code value in HTTP message.
-
-  @return                        Value defined in EFI_HTTP_STATUS_CODE .
-
-**/
-EFI_HTTP_STATUS_CODE
-HttpMappingToStatusCode (
-  IN UINTN                  StatusCode
-  );
-
 /**
   Check whether the user's token or event has already
   been enqueue on HTTP Tx or Rx Token list.
@@ -556,24 +543,6 @@ HttpTcpTokenCleanup (
   IN  HTTP_TOKEN_WRAP      *Wrap
   );
 
-/**
-  Generate HTTP request string.
-
-  @param[in]  HttpInstance       Pointer to HTTP_PROTOCOL structure.
-  @param[in]  Message            Pointer to storage containing HTTP message data.
-  @param[in]  Url                The URL of a remote host.
-
-  @return     Pointer to the created HTTP request string.
-  @return     NULL if any error occured.
-
-**/
-CHAR8 *
-HttpGenRequestString (
-  IN  HTTP_PROTOCOL        *HttpInstance,
-  IN  EFI_HTTP_MESSAGE     *Message,
-  IN  CHAR8                *Url
-  );
-
 /**
   The work function of EfiHttpResponse().