Fix wrong CLT formula
Merge pull request #3 from LluisRamon/patch-1

Fix wrong CLT formula.
Record Lluís fix in the changelog.
Fix typo in balls-and-urns table.

Reported by Soumya Basu.
Remove duplicate dictionary entries.

New versions of the translation package produce an error if duplicate entries
have been defined.
Merge pull request #1 from mavam/master

bringing up to date