[changed] form.validate([form]) argument is now optional

Call it without an argument to force full validation of a form's current input data
[added] formset.validate([form]) - equivalent to the Form version

Use to set a formset's data from a <form> or to force full validation of its current input data
[changed] Don't trigger a state change from (form|formset).validate()

There may be multiple forms/formsets being checked and a redisplay may not be necessary if they're valid, so make the user handle this
Updated README and quickstart example, added live quickstart version
Upgrade docs examples to React 0.12.0 & newforms 0.9 dev build