Update default configuration files
Inline deadlockGuardedWait and change the WaitElement add to only happen once, as it could lead to leftover waits that never got notified, leading to a dead database.
Merge pull request #2864 from rickardoberg/communitylockleak19

Community LockManager lock leak fix
Document the appropriate way to disable UDC.
Merge pull request #2863 from cleishm/1.9-default-config

Update default configuration files
Makes it possible to disable UDC through System property.

This change also makes UDC not fail if an invalid configuration
value is given, instead it interperts it as the default value.
Merge pull request #2872 from thobe/1.9-udc-configuration

1.9 UDC configuration