[merge] don't use 'dots' progress output on non-interactive runs

[John Arbash Meinel]

John Arbash Meinel has voted +1.
Status is now: Semi-approved
Comment:
I'm pretty sure this was already approved except for the name of 
DummyProgress. So it should be enough to just merge it.


For details, see: 
http://bundlebuggy.aaronbentley.com/request/%3Ce01316480707120056t6df33a22p9f6177e10b528e7d%40mail.gmail.com%3E