dunkelrot/elxml — pull request #7 by lordfriend (2014-08-21 09:18:12+00:00)
Title: add callback to workbook\'s save method

When I use the save method and response a file to browser, I found I got a empty file. After review the source code. I find the `workbook.save` is a async method but lack a callback.
I add a callback to the method and also accept exception instead just throw it.