add a navbar in site.jsl

I needed a navbar for some guide navigation. instead of a patch i attach here the jelly xsl template that produce a navbar from a <navbar/> tag.

this tag can have 'prev', 'toc' and 'next' attributes. If one is present a link is generated using the attribute value. This is not something big, altho i find it useful. Also please not im no jelly guru, and thus even if the double if/if sequence could certainly be made prettier..

<!-- process a guide-like navbar -->
<jsl:template match="navbar" trim="false">
<x:set var="_prev" select="string(@prev)"/>
<x:set var="_toc" select="string(@toc)"/>
<x:set var="_next" select="string(@next)"/>
<div align="center" class="navbar">
[
<j:if test="$

"><a href="${_prev}">previous</a></j:if>
<j:if test="$

">previous</j:if>

<j:if test="$

"><a href="${_toc}">toc</a></j:if>
<j:if test="$

">toc</j:if>

<j:if test="$

"><a href="${_next}">next</a></j:if>
<j:if test="$

">next</j:if>
]
</div>
</jsl:template>

example of use :

• developer-guide.xml : navbar next="guide/relationships.html"/>
• relationships.xml : <navbar toc="../developer-guide.html" next="building.html"/>
• buidling.xml : <navbar prev="relationships.html" toc="../developer-guide.html" next="guidelines.html"/>
• guidelines.xml : <navbar prev="building.html" toc="../developer-guide.html"/>