Locked door barriers

Added barriers to 3 doors: the two east doors that lead to the closets near the library. (One in the library, one in the east hall by the staris) Added locked door to the classroom just north of the original classroom.

Also added hide content the north closet in the library. It is a duplicate of the original classroom. This is not permanent. Its just to help me think about the content that should be added there eventually.