You seriously must use Download Accelerator Manager (DAM).
It is so amazingly powerful that even if you uninstall this manager with a download partially done, and you reinstall it, that partially done download actually resumes!!!!!
If you do not believe me, try it out for yourself. I am telling you my own experience. The actual intention of this is to download data as fast as possible.
I do not know if you can automatically assign downloads to it, you have to copy-past the link. But that sacrifice is nothing in front of the performance you get!
Happy downloading =)