Dont overwrite padding-left and padding-right (you can use grid-column()...

... after this commit.)

I have the fallowing problem in my project:
```scss
label {
	@include grid-column($columns:3, $collapse:false, $float:false);
	text-align: right;
	//@include form-label($alignment:inline, $base-style:false);
	margin: 0 0 $form-spacing 0;
	padding-top: $form-spacing / 2 + emCalc($input-border-width * 2);
	padding-bottom: $form-spacing / 2 + emCalc($input-border-width * 2);
}
```

I can't use the form-label mixin, because it would set `padding: $form-spacing / 2 + emCalc($input-border-width * 2);`. But because the grid-column() mixin uses padding-left and padding-right those would get cancelled out.

Not really sure if I should apply grid-column on a label in the first place?