[docbook-tc] modified <co> for HTML

[Bob Stayton <bobs@caldera.com>]

I just checked into CVS a modified html/callout.xsl.
This includes a modification to the <co>
XSL template for HTML output to use any linkends
attribute to form a link from the <co> bug
to its matching <callout> element.  That forms the
two-way link as described in The Definitive Guide.
Currently it only works with a single-valued
'linkends', because HTML doesn't support multiply-targeted
links.  

This change only works for using <co> in your screen or
programlisting, not for using screenco or programlistingco
with areaspec, because those are currently implemented
using extension functions.  

-- 

Bob Stayton                                 400 Encinal Street
Publications Architect                      Santa Cruz, CA  95060
Technical Publications                      voice: (831) 427-7796
Caldera International, Inc.                 fax:   (831) 429-1887
                                            email: bobs@caldera.com