title: How do I merge separate git repository into existing one
body: <p>I have a project which has its main repository on Bitbucket (let us say this is version 1).
  Someone else started working on this project and did so using his own local git repository. I now got his repository on stick. He did not branch or pull, but just created the project from 'scratch' with a new, fresh repo. Let us call this version 2.
  Now, how do I put the repo of version 2 back into the repo of version 1. I am willing to sacrifice all intermediate commits if needed as long as I can keep both the final version 1 and version 2 states.</p>