We use Team Foundation Server as our source control solution.  I am wondering what ability this has or if there are other tools out there for comparing versions of K2 Solutions?  We are in a situation where we are migrating applications to another environment.  We will have a current branch in TFS for whats in production now and a future branch for the changes we are making for the new.  If we have a break/fix come in for the current branch what i want to know is can we do a 'merge' like you can with Visual Studio solutions?  Or are we forced to make changes in both branches.  Thanks!