Fix yn dialog

Sometimes yn dialog returned False value, when an user provided 'y' (yes) answer. The reason of the behavior is comparing string by 'is' operator instead of '=='.

I've replaced the 'is' operator used in the comparison to '==' to correct the error.

I've also changed the 'src' directory name to the project's name - which easier the development (the supybot import works because the directory's name reflects the module's name) - if you don't want this, please tell me, I'll change the pull request, if you will see it worthy to merge ;)

Thank you ;)