Option to download to a folder named after the download

[AlecRust]

Is your feature request related to a problem? Please describe.
When downloading, the result of the download is not necessarily a folder, it may be many files that are output to the save location. Unless the user creates a new folder specifically for that download and then specifies that folder in the "Save To" dialog when starting a download, there can be many files from multiple different downloads output to the same location.

Describe the solution you'd like
An option for the download to be downloaded to a new folder (in the save location) with the name of the download. I don't see an option for this in Transmission but I believe it is the default behaviour, perhaps only if the download won't already result in a single folder containing the download contents.