Squashed 'external/git-number/' content from commit 00f7918

git-subtree-dir: external/git-number
git-subtree-split: 00f7918e07fbfd0cb323beb91873f819b9529a56
Merge commit '9ead5c6d083bc54dfe29d936826913810d1948f5' as 'external/git-number'
Update subtree commands