You can uninstall or removes an installed libhtml-wikiconverter-snipsnap package itself from Debian 8 (Jessie) through the terminal,
$ sudo apt-get remove libhtml-wikiconverter-snipsnap
If you would like to remove libhtml-wikiconverter-snipsnap and it's dependent packages which are no longer needed from Ubuntu,
$ sudo apt-get remove --auto-remove libhtml-wikiconverter-snipsnap
If you use with purge options to libhtml-wikiconverter-snipsnap package all the configuration and dependent packages will be removed.
$ sudo apt-get purge libhtml-wikiconverter-snipsnap
If you use purge options along with auto remove, will be removed everything regarding the package, It's really useful when you want to reinstall again.
$ sudo apt-get purge --auto-remove libhtml-wikiconverter-snipsnap