Break up downloads into 2 files: Data and metadata

[markuhen]

There has been a request to add back to our system the recognition of who entered most of the data and a suggested citation for the data download.

Part of this may be taken care of with our new data archiving system, but it still would be a good idea to acknowledge data enterers.

I think the best place for this might be the metadata block in a data download. While the metadata is EXTREMELY important, the first thing I always do is cut it out and save it elsewhere, because it gets in the way of using the data as a spreadsheet.

I think the way to fix these two issues is to download 2 files, with paired names. While we are messing with the downloader, let's force users to pick a name for the file(s), then download 2 files data and metadata with the given name plus the tags data and metadata.