jljvmregistry does not pass on doPost call if input param string is empty
jljvmregistry does not pass on doPost call to the rest of Jalama if the input
params string is empty. Should pass on the call no matter what input received,
and the JalamaController and/or Command object should take care of resolving.
This allows doPost to be used to call a Command that needs no input params (see
also bug #987 - null values should also be allowed)