Add support for OpenClosedItem

[Dbzman]

I took the chance to replace the copyright year as well.

[seaside1]

Looks good. I had some problems setting up my dev environment, but finally got it working.
I was considering naming The OpenClosedItem to ContactItem, but since it is named OpenClosed item in openhab-core it is probably best to have this name.

Only comment I have is that your IDEA transformed some of the imports to import *, i'll fix that in my next commit. Good work, and thank you for the contribution.

[Dbzman]

Yeah, I had similar thoughts on the naming and I think you're right. It's good to stick to the openhab-core. On the other side, I just took a look at the documentation again.
https://www.openhab.org/docs/configuration/items.html#type
I guess you named every item class after the "Type Name" column so far. Given that it may be better to use ContactItem.

I'll take a look at my IDE settings for the next time. Thanks for merging. :)