title: Git showing lots of changes and untracked files after checkout
body: <p>So I'm on a branch, let's call it <code>feature/PRO-10</code> and I want to switch to another branch to quickly check the state of a piece of code. I do a <code>git stash</code> to stash my changes and then a <code>git checkout bugfix/PRO-13</code> to go to the branch I want to look at code on. I finish what I want to do on this branch (without making any changes) and do a <code>git checkout feature/PRO-10</code> to get back to the branch I was developing on. I'm about to do a <code>git stash pop</code> but wait! There's a behemoth of modified and untracked files along with other changes.</p>
  
  <p>How did they turn up? I never did any sort of merge. I may have done a <code>git pull</code> to get up-to-date with <code>bugfix/PRO-13</code> but I don't see why that would make loads of changes that follow me to my original branch.</p>
  
  <p>The worst thing is sometimes I'll do a <code>git stash pop</code> before doing a <code>git status</code>, meaning I'll probably have my original changes mixed in with all this other gumph that seemingly came out of nowhere.</p>
  
  <p>Where are these changes coming from and are they safe to get rid of?</p>