serconf: add an option to display the help text
serconf: add support for a configuration file
serconf: add verbose and quiet option

By default, print out the device. To be used by calling script.
serterm: make use of the new fonctions of serconf

And add an option to display help.
serchrono: make use of the new fonctions of serconf

And add an option to display help.
remove space before colon

No space before colon in english.
Plus that's a perfect use-case for git-search-replace :)