fixed PHPDocs, + two functions
fixed PHPDocs, + two functions

added functions:

`getSessionHash()` -- Get current session hash, return string
`comparePasswords(int $userid, string $testpassword)` -- Compare $testpassword with password stored in DB for this $userid, return bool

changed visibility of `isEmailTaken()` function to public.

webot/PHPAuth,livmackintosh/PHPAuth,Wardevour/PHPAuth,ChristinMilloy/PHPAuth,KarelWintersky/PHPAuth,PHPAuth/PHPAuth