Added common friends list
Merge branch 'master' of https://github.com/IMSCoders/bitbook into DAL

Conflicts:
	BitBook.Repository/Interfaces/IPostRepository.cs
	BitBook.sln
ObjectId replaced for string in Users
Merge branch 'master' of https://github.com/IMSCoders/bitbook into DAL
logic changes for repos
use "safe" methods if possible
Merge branch 'master' of https://github.com/IMSCoders/bitbook into DAL