Quote sheet name if it starts with a number
Created originally on Bitbucket by chrisnic (Christopher Gross)
Changesets for this Pull Request have not been imported, because it had been already declined on Bitbucket. Marked as closed by the import user.
As it turns out, Excel needs sheet names to also be quoted if they start with a number. I have run into this problem with sheetnames named "1-something" and similar.