The Multilingual App Toolkit seems to be the culprit. I had the same issues as the OP, couldn't change file/folder names, move files etc.
I discovered that running Visual Studio 2013 Update 2 with the /SafeMode switch cured the problem temporarily.
Looking for a more permanent solution, I also tried uninstalling and reinstalling Visual Studio, but that didn't fix the problem. But once I removed the Multilingual App Toolkit the problem went away..
[EDIT]
It appears that reinstalling the Multilingual App Toolkit solves the problem too.