KNGConfig: when saving comments don't forget to respect file

Signed-off-by: Gregory M. Turner <gmt@be-evil.net>
config: split out EPREFIX-prefixed convenience constant

Signed-off-by: Gregory M. Turner <gmt@be-evil.net>
scripts/kernelng: SUBCMDHELP: fix indentation (consistency)

Signed-off-by: Gregory M. Turner <gmt@be-evil.net>
scripts/kernelng: help improvements

Signed-off-by: Gregory M. Turner <gmt@be-evil.net>
scripts/kernelng: file handling

o introduce --force option

o close outfile in example()

Signed-off-by: Gregory M. Turner <gmt@be-evil.net>