Include lastCommittedTransactionTime in Shard JMX
MBean
Changed the maximum-frame-size to a larger value

patch 2: rebased
patch 3: merge with other changes
patch 4: commit not returning if cohort was null, included failedTransactionsCount
patch 5/patch6: updated with review comments
patch 7: reformatted based on comment

Change-Id: I85218131dc8edb51f4c2c9fcbb34be79b547789c
Signed-off-by: Basheeruddin Ahmed <syedbahm@cisco.com>