Decoupling PHPExcel and Writers

[frost-nzcr4]

This update relates to the problem when you have set of PHPExcel objects and try to write all of them by using the writer, which has been configured once per set. To do this with current codebase one should instantiate the writer for each PHPExcel in the set, except Excel2007 and OpenDocument writers there get/setPHPExcel methods already in use. After this update you can use it with other writers as well.

So with update you can do this:

$lonely_writer = new Writer($phpExcel1);
$lonely_writer->save();
$lonely_writer->setPHPExcel($phpExcel2)->save();

instead of this:

$writer1 = new Writer($phpExcel1);
$writer1->save();
$writer2 = new Writer($phpExcel2);
$writer2->save();