All transfers are disappearing from TransferView when enabled/disabled

confirmed on windows 7 home premium 32 bit

i have tried to tackle this before but could not find any satisfying solution... please discuss the general direction(s) before going too far.

The attached patch was what I had intended and it works here, although it is incomplete.

i can think of 2 main directions:
A) add methods in event generating classes to retrieve lists of previously consumed events (what the patch is doing).
B) keep a cache on the observer side (the GUI).

pros of #B:
- no thread-related problems.
- easy to implement.

con of #B:
- consumes resources even when the transfer panel is hidden.

the only advantage i can see of #A is to avoid that resource consumption problem. i am wondering if it is worth the following cons:
1) retrieving connections is probably not enough; there are also downloads and (optionally) HTTP transfers.
2) thread safety (around the todo - std::copy / std::transfer might come in handy).
3) check what happens when the same event is received twice; once by the retrieving func, once through a regular callback.

The attached patch will take care of all connections and try and show them when you re-open...

The only thing that I could see is when you close a Connection (and still is closing), it won't show up when you re-open the window, but I don't think that that scenario occur very often and is kind of irrelevant as well.

Hm, I didn't see comment #4, I'll reconsider.