parallel/algo.h cleanup

[Jonathan Wakely]

On 25/09/16 17:23 +0200, François Dumont wrote:
>Hi
>
>    Trivial patch to cleanup parallel/algo.h by generalizing usage of 
>std::__iterator_category.
>
>    * include/parallel/algo.h: Generalize usage of 
>std::__iterator_category.
>    Adjust whitespaces.

N.B. for a patch of this size it would have been easier to review the
whitespace changes separately from the substantial changes.


>    Tested under Linux x86_64 parallel mode.

OK for trunk, but please also test normal mode before committing. It
shouldn't cause any problems, but best to be sure.