Add Proxy feature

[shadyabhi]

qbittorrent should have a feature like to use proxy only for getting tracker information & doing P2P from the direct connection. Doing this can be really useful because many places, its only the trackers that are blocked.
We have a similar feature in utorrent.

[acce]

The feature was available prior to version 2.5.X
You just have to regress to version 2.4.11 or older.
I was told that this feature would probably not come back.

[shadyabhi]

Looks like it can come back..

http://code.google.com/p/libtorrent/iss ... ail?id=155