#163 : Fix extra newlines bug on multiple use of same html2text object

[theSage21]

163

• The bug was being caused since self.start was retaining the False value
• I've added tests to ensure this does not regress.

[theSage21]

@Alir3z4 @jdufresne

It's been a long time since I contributed. I'd like to get this reviewed before merging.

[theSage21]

No idea why tests did not run.