function format( width, lines, fill, padding ) {
	var txt;
	var len;
	var i;

	// Format each slide line...
	lines = lines.slice();
	for ( i = 0; i < lines.length; i++ ) {
		txt = lines[ i ].text;
		len = lines[ i ].length;

		// NOTE: order matters (check first for full screen horizontal rule before regular horizontal rule)...
		if ( startsWith( txt, '//' ) ) {
			txt = rule( width, txt.substring( 2 ), len-2, fill, 0 );
		} else if ( startsWith( txt, '/' ) ) {
			txt = rule( width, txt.substring( 1 ), len-1, fill, padding );
		} else {
			txt = align( width, txt, len, fill, padding );
		}
		lines[ i ] = {
			'text': txt,
			'length': width // effective line length after alignment
		};
	}
	return lines;
}
Formats lines of slide text.

@private
@param {PositiveInteger} width - slide width
@param {ObjectArray} lines - lines of slide text
@param {string} fill - fill character
@param {NonNegativeInteger} padding - alignment padding
@returns {ObjectArray} formatted lines