RFC: sort parameter order

This pull changes the order of sort related routines to always put the vector to sort first.  When looking at the sort definitions, this make it slightly harder to see at first what is being defined, but from a user's perspective, I think it makes a little more sense, and is generally more consistent with the rest of julia (and DataFrames), where the item being operated on is usually first.

Sorting tests pass with this commit, though I'm getting a (presumably unrelated) build error in the arpack tests with eigs.