Fix pre-allocation in CDownloadQueue::CopyFileList
(upstream git commit f8f0eca00153b508831fce03c385fb2fb1c8ae66)
Don't log a critical line on startup if statistics.dat is missing
(upstream git commit 2de1d5fa97de56625459362cc6ccfd94dbf1c044)
Less writing of known files list during hashing (every 3000MB instead
of 300): files have become larger and hashing faster.
(upstream git commit f9b504a11ba7fabde6c7a63184edeeeb15ec7f66)
c576bd4f88