multisearch: new release

Just a minor update for the multisearch Weka package due to a feature request. The ListParameter expects by default a blank-separated list. This is mainly for allowing the user to supply multiple command-lines of other schemes, as they might contain commas or semicolons in their setup, rendering commas and semicolons unsafe to use as delimiter. However, I added an option for a custom delimiter, which allows the user to use a specific character instead for splitting the list string into separate items, making the command-line a bit less convoluted in cases where it is safe to do so.