tweak manpage formatting

This attempts to force fixed-font in manpages for literal
blocks.  I have tested this with docbook 1.71 and it seems to
work as expected.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/callouts.xsl

@@ -27,4 +27,17 @@
   </xsl:if>
 </xsl:template>
 
+<xsl:template match="literallayout[@class='monospaced']">
+  <xsl:text>.RS</xsl:text>
+  <xsl:if test="not($man.indent.width = '')">
+    <xsl:text> </xsl:text>
+    <xsl:value-of select="$man.indent.width"/>
+  </xsl:if>
+  <xsl:text>&#10;</xsl:text>
+  <xsl:text>&#10;.ft C&#10;.nf&#10;</xsl:text>
+  <xsl:apply-templates/>
+  <xsl:text>&#10;.fi&#10;.ft&#10;</xsl:text>
+  <xsl:text>.RE&#10;</xsl:text>
+</xsl:template>
+
 </xsl:stylesheet>