bug fix

features

Performing a draw between unlimited number of entries with different group sizes.
Ability to set a restricted_level for each entry to be able to distribute such
entries on different groups without putting two entries with the same restricted
level in the same group (if it's not possible, an error would be raised).
Ability to set an optional_level for each entry to be able to try to distribute
such entries on different groups without putting two entries with the same optional
level in the same group (if it's actually possible, otherwise optional level would
be ignored).
Detailed log output during each operation.