Merge branch 'jk/ui-color-always-to-auto-maint' (early part) into jk/ref-filter-colors-fix-maint

* 'jk/ui-color-always-to-auto-maint' (early part):
color: make "always" the same as "auto" in config
provide --color option for all ref-filter users
t3205: use --color instead of color.branch=always
t3203: drop "always" color test
t6006: drop "always" color config tests
t7502: use diff.noprefix for --verbose test
t7508: use test_terminal for color output
t3701: use test-terminal to collect color output
t4015: prefer --color to -c color.diff=always
test-terminal: set TERM=vt100

diff --cc Documentation/config.txt
Simple merge

diff --cc Documentation/git-for-each-ref.txt
Simple merge

diff --cc Documentation/git-tag.txt
Simple merge

diff --cc builtin/tag.c
Simple merge

diff --cc t/t4202-log.sh
Simple merge

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

diff --cc t/t7006-pager.sh
Simple merge