- uncomment-region doesn't work for some unknown reason
- comment-multi-line allows the use of multi line comments
- comment-extra-lines allows yet another style choice
- comment-add allows to default to `;;'
- comment-region on a comment calls uncomment-region
- C-u C-u comment-region aligns comment end markers
- C-u C-u C-u comment-region puts the comment inside a rectangle
