Validator API returns line numbers that are sometimes out by one when file contains an <?xml version?> element

[simon-20]

Brief Description
This occurs, at least, for 0.3.1 schema errors, and some others as well. The issue is that the <?xml version> element is added as and when by the running of xmllint, but the Validator code which produces line numbers for rulesets and codelists does not take this into account.

I have addressed the issue as far as new advisories are concerned.

Severity
Low