flag has been depricated, although it still works with a warning
message, and replaced with an environment variable CLICOLOR (command
line interface colour). This could be used by other tools that
want to be able to control colour output.
In addition if the environment variable CLICOLOR_FORCE is defined
colour sequences are output irrespective of whether the output is
directed to a terminal (as long as TERM references a colour capable
terminal of course ;)
PR: bin/20291 and bin/20483
3d2ddc9e1a