Connect timeout in qabstractsocket.cpp is too long

The QT_CONNECT_TIMEOUT constant in qabstractsocket.cpp is by default set to 30 seconds. This value is used in QAbstractSocketPrivate::_q_connectToNextAddress to determine when a connection attempt should time out.

This causes problems when trying to connect to an address that maps to a pool of IP addresses and a portion of those IP addresses is blocked for whatever reason.

Ideally this timeout value should be configurable.

A concrete example of this when trying to connect to binaries.eveonline.com from Russia. binaries.eveonline.com is hosted on Amazon's CloudFront, and Russian EVE players are reporting that individual IP addresses from the pool that this maps to are being blocked. The EVE launcher uses QNetworkAccessManager to download resources from this address. When some (or most) of the addresses are blocked, this can take a very long time when each connection made has to wait for a 30 second timeout before trying the next address in the pool.

This can be reproduced with the help of the Windows Firewall - use it to block most of the IP addresses returned by nslook binaries.eveonline.com.