Add a Makefile in place of all.bash

doc/contribute.html

 <!-- Contributing to the Go project -->
 
 <h2 id="Introduction">Introduction</h2>
 
 <p>
 This document explains how to contribute changes to the Go project.
 It assumes you have installed Go using the
 <a href="install.html">installation instructions</a> and
 have <a href="code.html">written and tested your code</a>.
 (Note that the <code>gccgo</code> frontend lives elsewhere;
 see <a href="gccgo_contribute.html">Contributing to gccgo</a>.)
 </p>
 
 <h2 id="Testing">Testing redux</h2>
 
 <p>
 You've <a href="code.html">written and tested your code</a>, but
 before sending code out for review, run all the tests for the whole
 tree to make sure the changes don't break other packages or programs:
 </p>
 
 <pre>
 cd $GOROOT/src
-./all.bash
+make all
 </pre>
 
 <p>
-The final line printed by <code>all.bash</code> should be of the form:
+The final line printed by <code>make all</code> should be of the form:
 </p>
 
 <pre>
 <i>N</i> known bugs; 0 unexpected bugs
 </pre>
 
 <p>
 The value of <i>N</i> varies over time, but the line must
 say &ldquo;<code>0 unexpected bugs</code>&rdquo; and must not
 add &ldquo;<code>test output differs</code>.&rdquo;
@@ skipping 459 matching lines @@
 This rigmarole needs to be done only for your first submission.
 </p>
 
 <p>Code that you contribute should use the standard copyright header:</p>
 
 <pre>
 // Copyright 2009 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 </pre>