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

Escaping email chars

Fix #126 

See merge request !112