Alessandro Vernet for a patch thats part of this commit
Toshiaki Kamoshida for a testcase and lots of debugging
Dennis Doubleday & Henning Boeger for reporting the bugs
Jason Height who wrote cloneSheet in the first place.
Sorry it took so long to patch.
git-svn-id: https://svn.apache.org/repos/asf/jakarta/poi/trunk@353017 13f79535-47bb-0310-9956-ffa450edef68