title: Git - Same file with different versions on two branches, when merge do not want to overwrite
body: <p>We have two branches -- 'master' and 'release'</p>
  
  <p>And we have one file, like <code>fileA</code>, we want to keep different version on these two branches.</p>
  
  <p>But each time, we have to merge 'release' into 'master', how can we achieve, the <code>fileA</code> in 'master' will not be overwritten by the <code>fileA</code> in branch 'release'.</p>