Issuing a move command to a different unit can stop building

[musshorn]

Reproduce:

1. Issue a build command to a worker
2. While they are walking to it, issue a move command to another worker
3. The initial worker clears all work and stops

Problem is in builder_queue, need to reconsider the concept of the player.activeBuilder I think.

[int128fly]

One thing to note, is the build cancelled callback is called everytime a right click actions is trigger (e.g. sell an item, move item to stash, ...)

[musshorn]

That's not really related to this issue. I thought i fixed this yesterday? http://gfycat.com/WideCircularGordonsetter

[int128fly]

Nice I will test this tonight, good job 👍

Sorry it my first time using the track issue on a open source project, hehe. I was wondering why my reported issue dispeared!