Improvements for initWithCoder: and MZDay getters

Hi,

Great stuff, your picker helped me a lot. However,  I was creating it from a XIB. Hence initWithCoder: was called. I removed the re-assignement of self, which I think is not a good idea, and factorised the setup. Somehow, the frame of the tableview isn't aligned with that of the mainFrame once the setup is done. I had to add a linen for that.

Finally, I added some automatic getters for MZDay I needed for my project. Hope this helps!
Cheers,

Cédric