Utility API, RFS option: Only generate responsive classes when needed

[MartijnCuppens]

I bumped into these classes which shouldn't be generated when responsive isn't set true:

bootstrap/dist/css/bootstrap.css

Lines 10631 to 10673 in b1290ff

	.fs-sm-2 {
	font-size: 2rem !important;
	}
	.fs-sm-3 {
	font-size: 1.75rem !important;
	}
	.fs-sm-4 {
	font-size: 1.5rem !important;
	}
	.fs-md-1 {
	font-size: 2.5rem !important;
	}
	.fs-md-2 {
	font-size: 2rem !important;
	}
	.fs-md-3 {
	font-size: 1.75rem !important;
	}
	.fs-md-4 {
	font-size: 1.5rem !important;
	}
	.fs-lg-1 {
	font-size: 2.5rem !important;
	}
	.fs-lg-2 {
	font-size: 2rem !important;
	}
	.fs-lg-3 {
	font-size: 1.75rem !important;
	}
	.fs-lg-4 {
	font-size: 1.5rem !important;
	}

[XhmikosR]

@MartijnCuppens Is this a regression from the RTL PR?

[mdo]

Is this a regression from the RTL PR?

I don't believe so—this looks like a mix up from rfs and responsive options maybe.