Solidity Natspec multiline /** .. */ comments

- Natspec now works with `/** ... */` type of comments.
- Some work on better formatting of the extracted text, especially on the multiline comments case
- Adding CR ('\r') as whitespace in the scanner
- Some tests
it can, but thinking back to the last time I combined if's to something unreadable I thought maybe this kind of code would be more readable, specifying the different "rules". Of course I can combine them but maybe it's more readable like that.