Add support for <dialog> tag.

fixes #2017
Improve debugging for methods using ReactPerf
Combine displayName using underscore
Add support for <dialog> tag's open attribute.
Fix broken link in animation docs

Missed in #2068
Merge pull request #2033 from pekim/master

Add support for <dialog> tag.
JSX spec blog post
Merge pull request #2106 from subtleGradient/subtleGradient/improve-ReactPerf-debugging

Improve debugging for methods using ReactPerf
added the missing **

Missed it the last time. Apologies.
Update Like button example verbiage

Changes text "You unlike this" to "You liked this". Makes a bit more grammatical sense.

Closes #2146.
Merge pull request #2147 from naman34/patch-2

added the missing **