Update PCbuild/readme.txt

It now recommends PCbuild/get_externals.bat instead of the scripts in
Tools/buildbot.
diff --git a/PCbuild/readme.txt b/PCbuild/readme.txt
index 65b75c3..c27af99 100644
--- a/PCbuild/readme.txt
+++ b/PCbuild/readme.txt
@@ -182,7 +182,7 @@
     to be somewhere on your PATH.  More recent versions of OpenSSL may

     need a later version of NASM. If OpenSSL's self tests don't pass,

     you should first try to update NASM and do a full rebuild of

-    OpenSSL.  If you use the Tools\buildbot\external(-amd64).bat method

+    OpenSSL.  If you use the PCbuild\get_externals.bat method

     for getting sources, it also downloads a version of NASM which the

     ssl build script will add to PATH.

 

@@ -236,45 +236,13 @@
 The last category of sub-projects listed above wrap external projects

 Python doesn't control, and as such a little more work is required in

 order to download the relevant source files for each project before they

-can be built.  The buildbots must ensure that all libraries are present

-before building, so the easiest approach is to run either external.bat

-or external-amd64.bat (depending on platform) in the ..\Tools\buildbot

-directory from ..\, i.e.:

-

-    C:\python\cpython\PCbuild>cd ..

-    C:\python\cpython>Tools\buildbot\external.bat

-

-This extracts all the external sub-projects from

-    http://svn.python.org/projects/external

-via Subversion (so you'll need an svn.exe on your PATH) and places them

-in ..\externals (relative to this directory).

-

-It is also possible to download sources from each project's homepage,

-though you may have to change the names of some folders in order to make

-things work.  For instance, if you were to download a version 5.0.7 of

-XZ Utils, you would need to extract the archive into ..\externals\xz-5.0.5

-anyway, since that is where the solution is set to look for xz.  The

-same is true for all other external projects.

-

-The external(-amd64).bat scripts will also build a debug build of

-Tcl/Tk, but there aren't any equivalent batch files for building release

-versions of Tcl/Tk currently available.  If you need to build a release

-version of Tcl/Tk, just take a look at the relevant external(-amd64).bat

-file and find the two nmake lines, then call each one without the

-'DEBUG=1' parameter, i.e.:

-

-The external-amd64.bat file contains this for tcl:

-    nmake -f makefile.vc DEBUG=1 MACHINE=AMD64 INSTALLDIR=..\..\tcltk64 clean all install

-

-So for a release build, you'd call it as:

-    nmake -f makefile.vc MACHINE=AMD64 INSTALLDIR=..\..\tcltk64 clean all install

-

-Note that the above command is called from within ..\externals\tcl-8.6.1.0\win

-(relative to this directory); don't forget to build Tk as well as Tcl!

-

-This will be cleaned up in the future; http://bugs.python.org/issue15968

-tracks adding a new tcltk.vcxproj file that will build Tcl/Tk and Tix

-the same way the other external projects listed above are built.

+can be built.  The easiest way to do this is to use the `build.bat`

+script in this directory to build Python, and pass the '-e' switch to

+tell it to use get_externals.bat to fetch external sources and build

+Tcl/Tk and Tix.  To use get_externals.bat, you'll need to have

+Subversion installed and svn.exe on your PATH.  The script will fetch

+external library sources from http://svn.python.org/external and place

+them in ..\externals (relative to this directory).

 

 

 Building for AMD64