PrepareCmd tests, use_package_optimistically

	modified:   lib/App/vaporcalc/Role/UI/PrepareCmd.pm
	modified:   t/role/ui/preparecmd.t
expanded Cmd::Subject tests

	modified:   lib/App/vaporcalc/Cmd/Subject/Help.pm
	modified:   lib/App/vaporcalc/Cmd/Subject/NicTarget.pm
	modified:   t/lib/cmd/subject/help.t
	modified:   t/lib/cmd/subject/nicbase.t
	modified:   t/lib/cmd/subject/nictarget.t
	modified:   t/lib/cmd/subject/nictype.t
	modified:   t/lib/cmdengine.t