Squashed 'vim/bundle/airline/' content from commit 2539745

git-subtree-dir: vim/bundle/airline
git-subtree-split: 253974506a49c47758e414c7fa4aceffd47c20e7
Merge commit '4a8c8892775cd4972c67f1478a95aa72b0fa65f7' as 'vim/bundle/airline'