Fix directory links in everything

xsl/tree.xsl

@@ -15,7 +15,15 @@
   <xsl:template match="file | directory">
     <xsl:param name="base" />
     <li>
-      <a href="{concat($base, '/', @name)}">
+      <a>
+        <xsl:attribute name="href">
+          <xsl:value-of select="$base" />
+          <xsl:text>/</xsl:text>
+          <xsl:value-of select="@name" />
+          <xsl:if test="self::directory">
+            <xsl:text>/</xsl:text>
+          </xsl:if>
+        </xsl:attribute>
         <xsl:value-of select="@name" />
       </a>
       <xsl:if test="@size">