+str - adds ZipWith and makes Zip use that to create tuples/pairs

@patriknw @ktoso @2m @bantonsson, do we want this one? Or is Flexi replacing all the things?
no, these are only here to help with inference when you'd like to define the ZipWith "in line" and java's inference can't figure stuff out.

On second thought, in-line defining `ZipWith` probably does not make sense (it does for linear things like flow/source, there we also have this style of methods). I have been adding this style of create() methods to java apis when initially implementing it in order not to omit something by accident. 

So I think this overload could be removed