added explanation
added ui to add new participating sites if the study is open
renamed service method
changed if statement
added text to explain the parameter (file path)
added not null check
set the acutal status and add an error text for trial right changes
add a check for the CurrentUser variable
show error messages from the configuration of the randomization method
fixed support for postgresql
fixed handling of DateConstraints (LocalDate instead of java.util.Date)