Fix typo in locale/en.json

Hello @olivierperez  
Following your comment in !122 I've just cherry-picked my commit and rebased it onto the release branch.  
Best regards

See merge request !131

Fix divBy0 if all info columns are disabled

Hiding all information columns results in a division by zero.

See merge request !128

Update german translation

Add missing translation of strings for german locale.

See merge request !130

Demande de confirmation lors de la supression d'une colonne.



See merge request !119

Empêcher l'ajout de colonne vide

Fix #123 

- Empêche l'ajout de colonne vide
- Permet la suppression des colonnes vides existantes
- Si l'on a une erreur lors de l'ajout de la colonne , on reste sur le formulaire d'ajout
- Correction de la date pour prendre le bon format par rapport a la langue

See merge request !118

Fix date picker

Fix #154

And more Smarty on poll creation

See merge request !115

Improvement - install

A check.php page before install
Updating config.tpl
Verification of config.php creation at install

See merge request !116

Feature : improve self editing vote

Adding a possibility to the user to enter his email address and to receive the personalized url by email.

See merge request !110

Config.php has bad encoding on install

Fix #142 

See merge request !114

Improvement of the email template to find polls

Fix #78 

See merge request !111