BaseTools: Remove unused txt files

externals.txt is to refer to the binary Win32. It is not used any longer.
BuildNotes.txt is to freeze BaseTools python. It is not used any longer.
BinaryFiles.txt is to list the file in Bin directory. But, Bin dir is empty.
building-gcc.txt and gcc is for mingw-gcc. It is not used any longer.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Liming Gao <liming.gao@intel.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Bob Feng <bob.c.feng@intel.com>

BaseTools/Source/BinaryFiles.txt

@@ -1,79 +0,0 @@
-## @file
-# This file lists all of the tool files that must be present in the Bin trees.
-#
-# This file is used by the EDK II Build Server that automatically builds the
-# BaseTools Win32 binaries.
-# When new tools are create, the tool executable must be listed in the [Bin.Win32]
-# section.
-# If a tool requires additional files, the developer must list those files in the
-# [ExtraFiles.Win32] section.
-# The [CxFreeze.Win32] section is maintained by the owner of the Build Server who
-# must ensure that files that are required by the cx_freeze frozen binaries are
-# present in the Bin\Win32 directory.
-#
-# Copyright (c) 2014 - 2018, Intel Corporation. All rights reserved.<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:
-#   http://opensource.org/licenses/bsd-license.php
-#
-# THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
-# WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
-#
-##
-
-[Bin.Win32]
-build.exe
-BPDG.exe
-Common.PyUtility.pyd
-Ecc.exe
-EfiCompressor.pyd
-EfiRom.exe
-Eot.EfiCompressor.pyd
-Eot.LzmaCompressor.pyd
-GenCrc32.exe
-GenDepex.exe
-GenFds.exe
-GenFfs.exe
-GenFv.exe
-GenFw.exe
-GenPatchPcdTable.exe
-GenSec.exe
-ImportTool.bat
-LzmaCompress.exe
-LzmaF86Compress.bat
-PatchPcdValue.exe
-Rsa2048Sha256GenerateKeys.exe
-Rsa2048Sha256Sign.exe
-Split.exe
-TargetTool.exe
-TianoCompress.exe
-Trim.exe
-UPT.exe
-VfrCompile.exe
-VolInfo.exe
-Pkcs7Sign.exe
-DevicePath.exe
-
-[ExtraFiles.Win32]
-TestSigningPrivateKey.pem
-config.ini
-exception.xml
-TestCert.pem
-TestCert.pub.pem
-TestRoot.pem
-TestRoot.pub.pem
-TestSub.pem
-TestSub.pub.pem
-
-[CxFreeze.Win32]
-_ctypes.pyd
-_hashlib.pyd
-_socket.pyd
-_sqlite3.pyd
-_ssl.pyd
-pyexpat.pyd
-python27.dll
-select.pyd
-sqlite3.dll