add git alias for checkout out PRs locally

git/gitconfig.symlink

@@ -78,6 +78,10 @@
     # Kaleidoscope commands
     dkal = difftool -y -t Kaleidoscope
     remotes = remote -v
+
+    # check out a local copy of a PR. https://gist.github.com/gnarf/5406589
+    pr  = "!f() { git fetch -fu ${2:-origin} refs/pull/$1/head:pr/$1 && git checkout pr/$1; }; f"
+    pr-clean = "!git for-each-ref refs/heads/pr/* --format='%(refname)' | while read ref ; do branch=${ref#refs/heads/} ; git branch -D $branch ; done"
 [color]
     diff = auto
     status = auto