Problem: Some problems with xxd coloring
Solution: Fix the following problems:
* Support colored output on Windows.
SetConsoleMode() is required to enable ANSI color sequences.
* Support "NO_COLOR" environment variable.
If "NO_COLOR" is defined and not empty, colored output should be
disabled.
See https://no-color.org/
* "-R" should only accept "always", "never" or "auto" as the parameter.
* Adjust help and documentation. "-R" cannot omit the parameter. Remove
surrounding brackets.
Related #12131closes: #12997closes: #12991closes: #12986
Signed-off-by: Christian Brabandt <cb@256bit.org>
Co-authored-by: K.Takata <kentkt@csc.jp>