Fix bug #56502 - When shifting XSSF rows with formula cells, if the formula can't be parsed, log + leave it unchanged rather than failing

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1614916 13f79535-47bb-0310-9956-ffa450edef68
Fix bug 54725 - HWPF where no parent style CHP exists, use an empty
 set when processing the style to avoid a NPE

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1614926 13f79535-47bb-0310-9956-ffa450edef68