Add EssentialsHandler to handle connections with Essentials.

Signed-off-by: Staartvin <mijnleraar@msn.com>
Move functionality from this class to PlayTimesUpdate class so it is
more organised and the update task is in sync with the save sync.

Signed-off-by: Staartvin <mijnleraar@msn.com>
Remove task from PlayerChecker class.

Signed-off-by: Staartvin <mijnleraar@msn.com>