Emitr shouldn't silently swallow errors in user code

[dchambers]

Emitr catches errors thrown by listener code, so that an error in one listener doesn't prevent other listeners from receiving the same event. Unfortunately, this prevents developers from becoming aware of errors within their code. Instead, emitr should log any errors to the console with code like this:

if(window.console) console.error(e);

[andy-berry-dev]

@dchambers Is this something for 1.1?

[dchambers]

@andyberry88, yes, that would make sense.

[ioanalianabalas]

Fixed by #11.

[improbable-adam]

It might be sensible to trigger a meta event in this case.