Various stuff

[FichteFoll]

• better debug logs in event.py
• update dependencies
• random ShadowAttributesMixin changes

In preparation for dev/python36 branch, which was branched from this.

[nitori]

Trying ctcp I noticed it fails at:

https://github.com/chireiden/shanghai/blob/dev/fichte/shanghai/core_plugins/ctcp.py#L69

ctx argument is not required (it's passed to object creation further up) in the dispatch method.

Maybe you want to add a fix for that as well?

The rest looks good and can be merged.