back up and restore complete exception state around 'finally' clauses; move current exception into sys.exc_info in Py3 to match Py3 semantics

Fix file header line for ELPA compatiblility

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extra : amend_source : c193bf636bba3b0f0439a25f1078e81a065b99fe

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extra : amend_source : f3b7f004f905c791e6ced2a5b27fffa21f9ceb08

The syntax follows that of template classes, namely

    cdef T foo[T](T, ...)

It's sensitive to compiler implementation.

disable exception check for special C return type (always assume that it's an exception when -1 is returned)

--HG--
extra : amend_source : 88f30462a27faf52fcee83af0d1dce714e4f7e69

fix crash when looking up closure names in OptimizeBuiltinCalls transform (after running CreateClosureClasses transform)

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extra : transplant_source : q%D5F8/%0B6%E2%B7R%F3%C9%E1%98%1B%E0X%A0%F1I