Changelog:
- regex.c (line_replace): Accept 's/^/#/g' as valid.
- main_loop.c: Removed length limit of prompt string.
- main.c: Set a valid invocation_name even if argc == 0.
- ed.texi: Extended operators depend on regex implementation.
- ed.texi: Several fixes and improvements.
Signed-off-by: Algent Albrahimi <algent@protonmail.com>