Disable automatic HA-JDBC database deactivation - EUCA-8954

Our custom HA-JDBC dialect is updated to prevent any errors being
interpreted as database failures. HA-JDBC scheduled failure detection is
removed.

With these changes only host activation changes in the cluster will
cause database activation changes. This means that the activation state
for databases will be consistent and determined by the coordinator.

EUCA-8954
UDP handler exit on closed socket - EUCA-7670

The UDPHandler now exits when the dns service is stopped.

EUCA-7670
Make context timeout configurable - EUCA-9076

EUCA-9076
Merge remote-tracking branch 'origin/dev/sjones/EUCA-7670' into testing
Merge remote-tracking branch 'origin/dev/sjones/EUCA-8954' into testing
Merge remote-tracking branch 'origin/dev/sjones/EUCA-9076' into testing