Fixed so upload.url returns the real url.
Fixed so upload.url returns the real url.

Before this commit the url method only prepended '/uploads/' which of
course is not correct if we use another MEDIA_URL.
Now we prepend MEDIA_URL instead which is much more sensible.

dtekcth/DNollK.se,Jassob/DNollK.se,Jassob/DNollK.se,Jassob/DNollK.se,dtekcth/DNollK.se,dtekcth/DNollK.se,Jassob/DNollK.se,dtekcth/DNollK.se