This is the patch by Jared Quick (mazungu@users.sourceforge.net) upgraded to fit svn 1693.
It will require a protocol change. I think that the functionality of the timer would actually need to be moved from the client to the server.
The modifications to eliminate free trade will be split from this patch.
Yes, the timer should certainly be in the server. It's a good feature, though. :-)
About the free trade: I don't think it should be forbidden. In some cases it is possible ("if you give me wood now, I'll give you two brick once I have them") But it could be good to give a warning before actually doing it.
I'm working on this patch. The functionality of the timer will be moved to the server.
The free trade has been implemented in r2276. Not protocol change was required. Pending for a release of Pioneers 15.6
Remaining task of this ticket: turn timers (controlled by the server)