Update trunk for new 1.9-SNAPSHOT development

git-svn-id: https://svn.apache.org/repos/asf/nutch/trunk@1578208 13f79535-47bb-0310-9956-ffa450edef68
NUTCH-1671 indexchecker to add digest field

git-svn-id: https://svn.apache.org/repos/asf/nutch/trunk@1578616 13f79535-47bb-0310-9956-ffa450edef68
NUTCH-1733 parse-html to support HTML5 charset definitions

git-svn-id: https://svn.apache.org/repos/asf/nutch/trunk@1580046 13f79535-47bb-0310-9956-ffa450edef68