Add feature to use comment deeper than level 3

I created the option to show comments deeper than level 3. For this to be working correctly, I also changed a couple of settings. It still is possible to set the max depth of comments you want to be visible in the TOC, but because from now you can't predict up front which depth will be the maximum, I chose 0 (zero) for all depths. Besides that, you can now choose also which character you would like to use in your TOC.

Malcolm Kindermans