Merge branch 'tb/config-default'

"git config --get" learned the "--default" option, to help the calling script. Building on top of the tb/config-type topic, the "git config" learns "--type=color" type. Taken together, you can do things like "git config --get foo.color --default blue" and get the ANSI color sequence for the color given to foo.color variable, or "blue" if the variable does not exist. * tb/config-default: builtin/config: introduce `color` type specifier config.c: introduce 'git_config_color' to parse ANSI colors builtin/config: introduce `--default`