OAK-1544: fix field widths and add BLOB column for big documents; add DB2 fixture

Changing the H2 DB url to create file in target folder otherwise the file get created under main folder causing rat plugin to fail

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1581714 13f79535-47bb-0310-9956-ffa450edef68