title: What is the difference between git subtree merge and git-subtree
body: <p>I've just found git-subtree tool that some time ago became a part of main git repo
  <a href="https://github.com/apenwarr/git-subtree/" rel="noreferrer">https://github.com/apenwarr/git-subtree/</a></p>
  
  <p>However I don't fully understand what functionality does this tool provide over the already existing "git read-tree" + "git merge -s subtree". Is the only purpouse of git-subtree - making the resultant commit history look better or does it have more functionality that I've overlooked?</p>