slixmpp 1.7.0 release

New plugins:

- XEP-0382: spoiler messages

Fixes and improvements:

- Fixes one critical bug of 1.6.0 preventing any reconnect
- Also change lots many things in the way connects and disconnects
  are handled
- Improvements to XEP-0199 to handle disconnects better
- Improvements to XEP-0198
- Improvements to XEP-0045 (more available stanza elements,
  typing issues, new helpers)
- Documentation fixes to update code that would only work with

Thanks to everyone for this release!