blind review on list-operations added by 2to3:

blind review on list-operations added by 2to3:
* some calls to list() were not needed
* some where linked to map() and replaced by [ for ]
* some constructions like for i in range(len(myiter)): were replaced by for item in myiter (and in rare cases together with enumerate)
* sometimes for k in d.keys() -> for k in d:
the plan is to will leave items() and values() and keys() in the code for both py2 and py3 ultimately, so no changes there in this commit