Allow blank cells to be ,, instead of ,"",

[tmaier]

A blank cell is currently interpreted as a string with 0 characters. This is why it is shown as ...,"",... in the generated CSV.

In some use-cases, a blank cell could mean null, which you would represent with ...,,...

It would be great if TableTool would default to the second or at least allow to configure the second as a default

[fulldecent]

Could you please review all the cases in the user interface where this would have to be changed. And can you please provide a mockup of what the proposed UI would look like?