Add ->export method to IRC::Mode::Set

Retrieves unblessed ARRAY (to drop overload magic)

	modified:   README.mkdn
	modified:   lib/IRC/Mode/Single.pm
	modified:   lib/IRC/Toolkit.pm
	modified:   t/03_irc_mode.t
Sanitize IRC::Mode::Set->clone* methods

new method: clone()
new_from_params -> clone_from_params
new_from_mode   -> clone_from_mode

Also always dclone mode_arrays

	modified:   lib/IRC/Mode/Set.pm
	modified:   t/04_irc_modechange.t