BOOKKEEPER-658: ledger cache refactor (Robin Dhamankar via sijie)

git-svn-id: https://svn.apache.org/repos/asf/zookeeper/bookkeeper/trunk@1531203 13f79535-47bb-0310-9956-ffa450edef68
BOOKKEEPER-638: Two bookies could start at the same time to access bookie data. (sijie via ivank)

git-svn-id: https://svn.apache.org/repos/asf/zookeeper/bookkeeper/trunk@1531302 13f79535-47bb-0310-9956-ffa450edef68
BOOKKEEPER-657: Journal Improvement (Robin Dhamankar via sijie)

git-svn-id: https://svn.apache.org/repos/asf/zookeeper/bookkeeper/trunk@1531494 13f79535-47bb-0310-9956-ffa450edef68
BOOKKEEPER-657: Journal Improvement (Robin Dhamankar via sijie) (add missing file)

git-svn-id: https://svn.apache.org/repos/asf/zookeeper/bookkeeper/trunk@1531495 13f79535-47bb-0310-9956-ffa450edef68
BOOKKEEPER-605: Use static Logger objects everywhere for bookkeeper (sijie via ivank)

git-svn-id: https://svn.apache.org/repos/asf/zookeeper/bookkeeper/trunk@1531920 13f79535-47bb-0310-9956-ffa450edef68
BOOKKEEPER-676: Make add asynchrounous in ledger recovery (aniruddha via ivank)

git-svn-id: https://svn.apache.org/repos/asf/zookeeper/bookkeeper/trunk@1531944 13f79535-47bb-0310-9956-ffa450edef68
BOOKKEEPER-673: Ledger length can be inaccurate in failure case (sijie via ivank)

git-svn-id: https://svn.apache.org/repos/asf/zookeeper/bookkeeper/trunk@1531970 13f79535-47bb-0310-9956-ffa450edef68