Login and logout implemented.

[+] View\Home : Added 2 methods.
[+] Control\Home : Added some case on the siwtch(controllerAction)  
[+] Foundation\User : Modified getByUsername(); now it returns false
if it doesn't find any user.
[+]Foundation\DegreeCourse.php : Modified getByName(); now it
returns false if it doesn't find any degreeCourse.