Stop propagation when selecting an entry

[Intrepidd]

See twitter/typeahead.js#1095

Selecting an entry doesn't stop the propagation, and causes a nasty effect when there are handlers on the keypress on a textarea, such as submitting the form.

This PR stops the propagation when pressing enter, as a default.

If you're not happy with it being a default, do you consider making it an option?

Thanks

[lenovouser]

Hm. I think making this default is okay, as it doesn't seem to break anything.

/cc @corejavascript/collaborators

[jcrben]

Couldn't this end up being a breaking change if the user depended on the event propogation? Seems unlikely but still possible.

I think this should project should ultimately use semantic versioning, but we could probably hold off on that until the first release is complete. We should probably summarize the changes in the release notes and note which ones could break backwards-compatibility.

So 👍 I guess.

[core-system-dev]

I second @jcrben

@Apfeluser do you mind adding a commit with this change to the release notes for v0.11.2 when this gets merged?

[jarthod]

Indeed it is worth telling the user in the changelog so he can find the reason easily if he was depending on this. Otherwise this is definitely a better default behavior. 👍

[lenovouser]

@CoreSystemDevelopment 3d929c8