Do parse recursive `elements` in schema

I didn't get why do you forbid recursive elements parsing in 68ef40e996e034f2f4bb23c0ca4454f10f4d9a60 and 9b07c32261050d897b55d83720fa863ada63f18e . There is no comment, ticket, bug report or testcase.

I've faced with bug — I have tree structure `HumanTaskTypeInfo` in my WSDL ( http://pastebin.com/pSn4P4mH ). Current version of `pysimplesoap` just drops `subtask` element from schema in parsing step and fails when receives this field from server on second.

I was really surprised then I've removed described lines — everything had been parsed well, no recursion, executed successfuly. Even unittests didn't report any bugs.

Pre- 68ef40e996e034f2f4bb23c0ca4454f10f4d9a60 version works good for me too.

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And small fix to my previous PR (about `style`).