CRQ-320: set serialVersionUID to fulfill upgradability

git-svn-id: http://svn.terracotta.org/svn/ehcache@8787 b9324663-ca0f-0410-8574-be9b3887307d
CRQ-320: merge serialVersionUID fix from trunk

git-svn-id: http://svn.terracotta.org/svn/ehcache@8788 b9324663-ca0f-0410-8574-be9b3887307d
CRQ-320: merge serialVersionUID fix from trunk

git-svn-id: http://svn.terracotta.org/svn/ehcache@8789 b9324663-ca0f-0410-8574-be9b3887307d