Update Concordia to latest version .
Allow for null wifi_data object. The wifi_data object is marked as optional in the stream definition, but this older mobility code was never updated to reflect that.
Prevent overwrite of audit information from superclass. Closes #211
Optimized stream read SQL
Added testOnBorrow to avoid the case where MySQL's wait_timeout config setting is smaller than our minEvictableIdleTimeMillis value.
Added FORCE INDEX to force MySQL to use the correct index for the stream read API
Added osd_duplicate_data_point_read index
Revert observer_stream_data default character encoding to UTF-8. It was UTF-16 due to a legacy bug fix attempt, but in practice our servers are all using UTF-8.
fixed conflict