Login via OpenID

Now this allow user to login via multiple OpenID accounts, I'll implement the web part after this and see if it will confuse the Interface part or I can fix it later if I find using just one account is more suitable. Any idea ? :)
@tsibley  I think I made it as an attribute of this class with `lazy => 1` the will make this class  will generate sid only when the class is initialized and will keep this for a while. I tried to to use '$self->_build_sid' I found that the that key change every request as you mentioned but it doesn't change if I use it as attribute with builder supply. Is it stable enough ? what do you think ?