Changed input of recursive kurtosis to window length
Modified test to give window length as kurtosis parameter
Start sigma=x(0) in kurtosis (no need to normalize)
Propagated rec_kurtosis change
Revert "Start sigma=x(0) in kurtosis (no need to normalize)"

This reverts commit 1a405376e7097de02ba8de4f7fbcb95ff10aaa92.
Unskip processing