function include( arr, pattern ) {
	var out;
	var i;
	out = [];
	for ( i = 0; i < arr.length; i++ ) {
		if ( arr[ i ].indexOf( pattern ) >= 0 ) {
			out.push( arr[ i ] );
		}
	}
	return out;
}
Filters an array by including those elements having a provided substring.

@private
@param {StringArray} arr - input array
@param {string} pattern - pattern used to filter elements
@returns {(EmptyArray|StringArray)} filter array