updated util
delete submodule util, replace with subtree
Squashed 'util/' content from commit 48630c4

git-subtree-dir: util
git-subtree-split: 48630c4f7fe549aa0725bb9506ee2a373047b3eb
Merge commit 'c11a12d0575a7a15b73b9edd9d65b2893685816c' as 'util'