You don't have to browse the Craigslist "Rooms for Rent" section very long before realizing that there are many tenants out there looking for "not just a roommate, but a FRIEND." This weekend's Times Real Estate section follows the journey of one 3BR LES apartment trying to figure out the right balance between being friendly roommies, but not BFFs. One tells them of a horrific summer she had where a roommate was seldom home, “and I got really lonely,”