[redland] configure w/ no libxml

[Seth Ladd]

Hello!

I've just pulled down redland 0.9.12 as a source dump, and trying to 
configure it.  When I specify ./configure --with-xml-parser=expat, it 
seems as if the raptor configure still wants to find libxml (which I 
don't have at the moment).

The messages I get from raptor's configure are:

checking whether need to declare optind... no
checking for expat sources... no
checking for main in -lxmltok... (cached) no
checking for XML_ParserCreate in -lxmlparse... no
checking for XML_ParserCreate in -lexpat... no
checking for working expat in libxmlparse and libxmltok... no
checking for working expat in libexpat... no
checking for xml2-config... no
checking for xml-config... no
checking for libxml sources... no
checking XML parser to use... configure: error: No XML parser available 
- please install expat or libxml
configure: error: ./configure failed for raptor

I'll pull down libxml, which is no problem.  Just wanted to pass this along.

Thanks for all your great work on a wonderful library,
Seth