Add note about test-suites to guidelines

This was discussed a while back but it was never added to the
guidelines.

next/guidelines.html

@@ -849,6 +849,13 @@ See <a href="rules.html#rule17">Rule 17</a> and in particular the part about the
 number of files</a>. If you do not follow these points, you
 are at a great risk of violating <a href="rules.html#rule17">Rule 17</a>!
 </p>
+<p class="leftbar">
+<strong>NOTE</strong>: if you want to include a test-suite that requires a lot of files,
+please suggest this in your <code>remarks.md</code> and if your submission wins it can
+be done. In other words you should not use a tarball for a test-suite unless you
+have a very good reason for this (and if you do, make <strong>SURE</strong> you specify why
+in your <code>remarks.md</code>).
+</p>
 <h1 id="mkiocccentry"><code>mkiocccentry</code></h1>
 <p class="leftbar">
 <a href="rules.html#rule17">Rule 17</a> (the <code>mkiocccentry(1)</code> rule) states that