Luke Champine authored Jul 16, 2016 and David Vorick committed Jul 16, 2016

* collect download contracts properly

Using a reference in the for loop caused the map to wind up with
only 1 entry, since the same pointer is used for each iteration.
To fix this, the map variable was abandoned in favor of a custom
slice. Although more unwieldy, there is less chance of misuse.

* sort contracts by value

* add TestSortByValue

* add regression test