Fix behavior of ReactDOMSelect

Closes #250.

Test Plan:
With multiple and not, verified: With defaultValue, the correct option is picked initially, user changes change the selection, and changes to defaultValue have no effect. With value, the correct option is picked initially, user changes do nothing, and changes to value change the selection.

Also ran the tests.
Merge pull request #251 from spicyj/select-value

Fix behavior of ReactDOMSelect with `defaultValue`
Make getChecked, getValue, handleChange private

Test Plan: grunt test, enter text in ballmer-peak example without any JS errors.
Merge pull request #275 from spicyj/input-private

Make getChecked, getValue, handleChange private
typo fix
Allow DOM Nodes in ImmutableObject

Currently, `ImmutableObject` will stack overflow while it tries to recurse and deep freeze all the properties of a DOM node.
Merge pull request #277 from stoyan/patch-1

typo fix
Added PyReact blog post.
fix textarea `value` of number 0

previously, setting `value` to number 0 is treated as if `value` wasn't set at all (thus the textarea is cleared from 0 to '' upon `onChange`.
clean way of fixing textarea value of number 0
remove useless conditional on input and textarea
test cases for input value of number 0
display "" when input/textarea value/defaultValue is false
Merge branch 'textarea-patch' of https://github.com/chenglou/react into textarea-patch

Conflicts:
	src/dom/components/ReactDOMInput.js