Fix for https://webarchive.jira.com/browse/ARI-4024
Merge pull request #39 from vonrosen/ari-4024

Fix for https://webarchive.jira.com/browse/ARI-4024
Add a test case catching ARI-4010: XML parser error due to head insertion before XMLDecl.
FIX allow XMLDecl to happen before HTML.
Fixes ARI-4010.
Merge branch 'ARI-4010' into ait-qa