Add printhdr(), replacement for printheader() with ANSI attribute

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

ChangeLog.md

@@ -10,6 +10,7 @@ All notable changes to the project are documented in this file.
 - Add support for `strmatch()` and `strnmatch()`
 - Add support for `yorn()`, safe yes-or-no prompt
 - Add support for telnet expect/session APIs
+- Add modified `printhdr()` which takes ANSI attribute
 
 ### Fixes
 - Fix `pidfile_signal()`: always return result of `kill()`, or the