c() does not work on SummarizedExperiment

[lawremi]

I would have assumed that c() would be equivalent to rbind() on SummarizedExperiment. However, it fails, because bindROWS,Vector() does not handle the assays. Perhaps rbind,SummarizedExperiment() should be refactored into a bindROWS() method?

[mjsteinbaugh]

I wrote a combine() method to merge multiple SummarizedExperiment objects, for reference: https://github.com/acidgenomics/basejump/blob/master/R/combine-methods.R