As segwit is active on testnet, blocks will only be downloaded from NODE_WITNESS peers. Though, exactly those peers are disconnected after `BLOCK_STALLING_TIMEOUT = 2` seconds. I am running master (6e6ab2c)

This behavior is consistent across restarts. Sample [debug.log](http://pastebin.ubuntu.com/23058327/) and [getchaintips](http://pastebin.ubuntu.com/23058325/).

It is possible that I shot my own foot at some point, but it seemed smelly enough to create an issue.

{
    string strStatusBar;
    string strRPC;
    string strGUI;
    const string uiAlertSeperator = "<hr />";
    if (!CLIENT_VERSION_IS_RELEASE) {
        strStatusBar = "This is a pre-release test build - use at your own risk - do not use for mining or merchant applications";