[CWB] Illegal division by zero

[Stefan Evert]

> Whilst the user should ensure that their data is correct perhaps a sanity check in those perl scripts is needed; "oy mate, you've not set the number of words per sentence properly".

In fact, there are lots of places in the Perl scripts that could do with (additional) sanity checks, but one look at the code usually convinces people not to try and make modifications ... :-}

Stefan