Update jquery.flot.hiddengraphs.js

remembers if it was a line or a point plot and maintains this when un-hiding.

I also removed the " [hidden]" from being added to the label because I thought making it gray was enough indication, and added an unbind on the mouseclick because it was firing twice the first time I clicked the label.
Update jquery.flot.hiddengraphs.js

fixed the formatting (spaces/tabs)
Fix coding style; remove unrelated longlabel setting; restore setData() hack.