Audit changes
audit changes in scribe_server/store_queue/store files to create audit messages for sent/received msgs
Refactored audit changes to separate files scribe_audit.[h/cpp], added synchronization to update audit counter, supported new fields in audit idl
Added try/catch block in scribe_audit.cpp for failure handling; refactoring in store.cpp
1) Added new fields in audit thrift; 2) renamed audit to _audit; 3) optimization in scribe_audit.cpp to first check timestamp before acquiring read lock
Set isAudit default false in ctor; log message changes
Merge branch 'master' into audit
Add support for hdfs tier audit
1) Ensure that audit store thread doesn't close out of order in shutdown 2) Add documentation of audit feature
Merge pull request #8 from InMobi/audit

Add Audit Trail feature in scribe