function filter( files ) {
	var out;
	var i;

	out = [];
	for ( i = 0; i < files.length; i++ ) {
		if ( RE_JSON.test( files[ i ] ) ) {
			out.push( files[ i ] );
		}
	}
	return out;
}
Filters a file list.

@private
@param {StringArray} files - file list
@returns {StringArray} list of filtered files