bitcoin/bitcoin — pull request #4816 by laanwj (2014-09-02 10:07:16+00:00)
Title: Change CNode::askFor to a deque

AskFor() guarantees that entries will always be added with a monotonically increasing timestamp.

```
int64_t nNow = GetTimeMicros() - 1000000;
static int64_t nLastTime;
++nLastTime;
nNow = std::max(nNow, nLastTime);
nLastTime = nNow;
```

This means that there is no need to use a map as event queue. This avoids some overhead. Also limit the maximum size of the structure.