renamed ReactOnDOMReady module to ReactMountReady

fix

renamed ReactOnDOMReady module to ReactMountReady
Sync getActiveElement module from FB.
Fix SelectEventPlugin

There were 2 issues:

I was reusing event outside the original event handler (activeNativeEvent).
This is a bad idea. I've changed deferred dispatch to have an empty object
as the nativeEvent.

I didn't handle inputs without .selectionStart (e.g. file inputs). I extracted
a input type check from ChangeEventPlugin and reuse it here.
fixed broken link on Community Round-up #9 blog post

closes #409
Merge pull request #407 from Samangan/master

renamed ReactOnDOMReady module to ReactMountReady
Tweak verbiage about required polyfills

I found it weird how the es5-shim comment came after the list of functions; now it's before.