...that git lets you move and rename whole directories while preserving the git history of those files?

If you run

git read-tree --prefix=$NEW_PATH -u master:$OLD_PATH
rm -rf $OLD_PATH
# ...you probably want to change some imports...
git commit -m $MESSAGE

that will move the directory tree to the new location, and, when you commit, it'll preserve this history of those files.

Things that still work:

• git blame
• git merge with code that branched off before the renaming (incredible!)