libxml-devel and libxml2-devel to coexist:
- Makefile.am configure.in libxml.spec.in example/Makefile.am:
  Changed the library name, in order to get libxml-devel and
  libxml2-devel to coexist on a single system
- xml-config.1 xml-config.in xmlConf.sh.in: renamed
- xml2-config.1 xml2-config.in xml2Conf.sh.in: new files
Daniel