title: Cannot Merge due to conflict with UserInterfaceState.xcuserstate
body: <p>I created a branch and made a bunch of changes. I committed the changes and then archived the changes. Then I switched to the master branch and tried to do a merge. It said I had uncommitted changes. So I did a commit on the master branch to see what it was talking about. It said that there is a file called UserInterfaceState.xcuserstate that was modified. So I committed the change (not sure what the change was). Then I tried to merge again. It then opens up a merge window and indicates that there is a conflict with UserInterfaceState.xcuserstate. So I went back to the branch and found that that same file is now needing to be committed. This did not show up before. So I committed it and went back to the master branch. Again I tried to merge but cant because of uncommitted changes. Sure enough, UserInterfaceState.xcuserstate is once again needing to be committed. I committed it and tried to merge. Same problem with conflict. Its a vicious circle.</p>
  
  <p>What is this file and how do I resolve the reported conflict. It does not show up in my project navigation window. Furthermore, it is not in the unix file system. I am totally stuck. Suggestions? I am using xcode 4.5.2</p>