docs section for non-dom attributes

Also added documentation for `dangerouslySetInnerHTML`.
Document the Diff algorithm

We often refer to it but never did actually explain it.
Add video at the bottom of the front page
Update highlighted lines in tutorial

Minor issue, but I found it distracting that the highlighted lines were not accurate. I *believe* this fixes them up.
rename this tip to be less confusing

Using props to initialize state is completely fine; the issue is using state as a "cache" for values calculated based off of props. This title makes it more clear.
fixing capitalization
Fix typo (ot -> to)
adding note about initializing state w/ props
changes as requested
one liner
Tutorial template markup needs a reference to jquery for the ajax calls
from step 13 onwards.
docs add input attrs for Dom Differences
docs make all link start with /react/docs
Simple HTML to JSX converter, built during Hackathon 40 at Facebook.

See /react/html-jsx.html. Not directly linked from the site yet as there may still be some minor issues with it.