Update ChangeLog for 1.9.3.

https://github.com/ariya/phantomjs/issues/11904
Update ChangeLog for 1.9.6.

https://github.com/ariya/phantomjs/issues/11905
ChangeLog for 1.9.7.

https://github.com/ariya/phantomjs/issues/11919
Remove CoffeeScript support.

https://github.com/ariya/phantomjs/issues/12410