reduceResultsExperiments and non-atomic results

[krlmlr]

I've been looking for a way to collect the result "as is" in reduceResultsExperiments(). The following function (used in fun) worked for me:

collectAsIs <- function(job, res) {
  list(res = I(list(res)))
}

The result is a single column res that is a list of the unmodified results.

How about exporting the default fun implementation (e.g., as collectIdentity) and also exporting the collectAsIs function above? I'll be happy to supply a pull request.