"Unresolved reference to User" after importing as a VS DB project

I just imported an existing SQL Server 2008R2 production database into a VS 2013 database project. I now get a number of errors along the lines of Error SQL71501: User: [mydbuser] has an unresolved reference to Login [mydbuser]. I don't really need my VS DB project to manage users, but I'm concerned that it would try to remove them upon deploy if they weren't there. The files themselves are generated as CREATE USER [mydbuser] FOR LOGIN [mydbuser]; or CREATE USER [mydomainuser] FOR LOGIN [MYDOMAIN\mydomainuser]; The error marker shows that it's specifically for the **Login**. As that's a system-level object, I can understand it being outside the scope of the db project. Is it preferred that I change them all to CREATE USER [mydbuser] WITHOUT LOGIN; or add the CREATE LOGIN clause to the beginning of each file? Removing the Login reference seems to be simpler and removing the users altogether would be the simplest. I want to make sure that I'm using the tool the way it was intended. - Will there be any issues in re-publishing any of those back to production? - What is the proper procedure for adding a user/login via a project?