Merge branch 'jk/ref-filter-colors-fix'

This is the "theoretically more correct" approach of simply
stepping back to the state before plumbing commands started paying
attention to "color.ui" configuration variable.

Let's run with this one.

* jk/ref-filter-colors-fix:
tag: respect color.ui config
Revert "color: check color.ui in git_default_config()"
Revert "t6006: drop "always" color config tests"
Revert "color: make "always" the same as "auto" in config"

diff --cc Documentation/config.txt
Simple merge

diff --cc builtin/branch.c
Simple merge

diff --cc builtin/clean.c
Simple merge

diff --cc builtin/grep.c
Simple merge

diff --cc builtin/show-branch.c
Simple merge

diff --cc builtin/tag.c
Simple merge

diff --cc color.c
Simple merge

diff --cc config.c
Simple merge

diff --cc diff.c
Simple merge

diff --cc t/t6300-for-each-ref.sh
Simple merge

diff --cc t/t7004-tag.sh
Simple merge