Versioning

I have been looking for a wiki to use as a online authoring tool to write a book. I would like to be able to not be tied to a particular computer. But to be able to access and write to it from anywhere.

My criteria have been
1 versioning so that I can roll back changes,
2 wysiwyg editing,
3 ability to lock out editing by others (user permisions),
4 the ability to save page or pages in correct order to a pdf.
5 Also nice but not critical would be spell check.

So far I haven’t found anything that is simple to install and use or that has all of these features.

I have used wordpress since before it was wordpress and got to thinking that it has most of the features already built into it. Just needing versioning added to the pages editing and a wiki like way to link the pages that a export to pdf function could follow.
so feature requests would be
1 versioning of either posts or pages or both.
2 integrated pdf export of selected pages/posts in order

thanks a lot for a great product