proper fix for #547 - e0c11818ea190b9e4a6c8cd06b911909ede742e0 did not solve the problem for arrays, and also removed the ability to set undefined arguments in callbacks (that was restored in 7f99616f7596e298809efd49d2de548db39bc4c4 though). Now, the generated query string gets decoded again, which means we're back to the old behavior where callback onGenerate methods are required to set rawurlencoded values (unless you don't want the encoding for whatever reason).