Fixed processing and passing of exceptions

Now exceptions from server methods are passed with stack trace to the client.

Please review.
But even better, here you can use string slicing instead of charAt, so all together

```
  string = string?.replace /\s+$/, ''
  if string?[-1..] not in ['.', '?', '!', ',', ';', ')']
    "#{ string }."
  else
    string
```