Name conflict in traverse function

[eastlund]

I think a minor oversight was made when merging #188. In version 4.8.0.0 of base, Prelude contains a traverse function already, thus a name conflict occurs when compiling some .hs files that use the recently added local traverse function. I guess that @EliasC and @albertnetymk don't use the 4.8.0.0 version of base (it should be supported) and therefore didn't notice the name conflict.

Here's the error I'm getting when building: https://gist.github.com/eastlund/43f19b6986f50c08527a, the error occurs in other files as well though.

[albertnetymk]

Yes, I introduced that name. Could reproduce the problem using base 4.8. I will rename it to sth else. Fix on the way.