Added support for counting entities matching a given query.
Fixed invalid EL expression causing the data table selection event listener to not work anymore.
Added support for counting all persons available for being marked or unmarked as discipleship teachers.
Implemented marking or un-marking persons as discipleship teachers.
Fixed one-to-one relation to ensure that the discipleship teacher is correctly persisted or removed.
Fixed an issue related to lomobok libary causing a StackOverflowError.