Merge pull request #524 from rleigh-dundee/genshi-diag

xsd-fu: Issue a warning if genshi is not available
cpp: replace usage of removed MetadataTools methods

This fixes compile errors introduced by 6b31a4ff9ac4bfc1ccf356804add10dc637366f5
merge develop -D org -I include -E exclude: PR 525 (cpp: replace usage of removed MetadataTools methods)