I noticed that my Concrete 5.6 site has a fairly significant amount of data in the files/tmp folder, much of it over 2 years old. For example, on .zip file contains most of the files I uploaded (presumably because I downloaded them in bulk one time so it put them all into a zip file), others include all of the add-ons and themes I have downloaded and installed. I know these files are just temporary, but shouldn't they be getting cleaned up? I couldn't find anything in the documentation or even the forums about this.

Is this content safe to delete? Is there any way to perform maintenance on this folder form within Concrete. And, does this occur on 5.7 (I have just started re-developing the site in 5.7)?