Initial check-in of API docs

I've still got a lot of work to do yet on the documentation extractor, but here's a demo of what the output looks like:

• Package index: http://docs.tart.googlecode.com/hg/api/index.html
• Module tart.core: http://docs.tart.googlecode.com/hg/api/package-tart-core.html
• Class String: http://docs.tart.googlecode.com/hg/api/class-tart-core-String.html

Note that I've coded all of the pages in HTML5, taking maximum advantage of <section>, <nav>, web fonts, css3 shadows, and so on.

Also note that a lot of the links still lead no-where, template parameters aren't being rendered, advanced formatting isn't finished, base classes aren't listed, and lots of other stuff.

Let me know what you think.