Merge branch 'cc/replace'

* cc/replace:
Documentation: talk a little bit about GIT_NO_REPLACE_OBJECTS
Documentation: fix typos and spelling in replace documentation
replace: use a GIT_NO_REPLACE_OBJECTS env variable

diff --cc cache.h
Simple merge

diff --cc connect.c
Simple merge

diff --cc environment.c
Simple merge

diff --cc git.c
Simple merge