explore non-Message activities

[billba]

e.g. should typing make it to/be ignored by a Prompt?

[Stevenic]

As an FYI... In botbuilder-dialogs we currently let all activity types through but most of the prompts are coded to only respond to 'message' activities. We had to do this to support the new OAuthPrompt which needs to look for 'message', 'event', and 'invoke' activities to work properly.

We also had to change our boilerplate routing logic to not filter out non-message activities as well because of this.