Merge branch 'tb/add-renormalize'

"git add --renormalize ." is a new and safer way to record the fact
that you are correcting the end-of-line convention and other
"convert_to_git()" glitches in the in-repository data.

* tb/add-renormalize:
add: introduce "--renormalize"

diff --cc builtin/add.c
Simple merge

diff --cc cache.h
Simple merge

diff --cc read-cache.c
Simple merge

diff --cc sha1_file.c
Simple merge