Added escaping for install in config.tpl

In the installation process, string like the one below should be a valid application name (or DB password).
> Framadate c'est vraiment super ! "Datez" comme vous voulez \o/

It missed some escaping for single quote (') and backslash (\\), resulting in PHP parse errors.

It should be cherry-picked to the `release` branch too.

See merge request !136

Fix edition limits for expired polls

Fix #129 

See merge request !117

Correcting escaping in create_poll.php

In create_poll.php, removing of the php escaping and completion of the template ones.

See merge request !134

Add editorconfig file



See merge request !123

Avoid warnings due to non-existant 'en' datepicker locale

There is no 'en' Translation of datepicker. Hence, do no try to load it.

See merge request !127

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