Use @Index in AbstractMailboxMembership (IMAP-165) + Use @ElementJoinColumn in AbstractJPAMessage (IMAP-180)
Use @Index in AbstractMailboxMembership (IMAP-165) + Use @ElementJoinColumn in AbstractJPAMessage (IMAP-180)

git-svn-id: 2601453adc5e6cbd1036d5a9801c88d5b249288f@980483 13f79535-47bb-0310-9956-ffa450edef68

mbaechler/james,tools4origins/james,ricardovhz/james,idtrust/james