(cherry picked from commit 6751a8a9)

Conflicts:
	adminstuds.php
	app/classes/Framadate/Utils.php
	creation_sondage.php

(cherry picked from commit e6d171a4)

Conflicts:
	app/classes/Framadate/Utils.php

Cherry-picked :
        e6d171a4

Conflicts:
	app/classes/Framadate/Utils.php

* Use Smarty to split View and Controller on studs page (work in progress)
* Add field "active" to Poll
* And some other stuff...

* Utils::issetAndNoEmpty is now removed
* Use Form object to store value from page to page

* Rename fields in Sondage table
* Add field "editable" which tells when users can edit their votes
* PDO : Configure 2 options (FETCH_OBJ + ERRMODE_EX)
* "formatsondage" does contains "+" (or not) anymore

* Store all informations about forms into an object "Form" stored in $_SESSION['form']
* Replace connection to database by PDO object
* Check if database is ready in bandeaux.php file