title: Is initialState in a mixin merged with initialState in a component?
body: <p>Simple question : if component A declares <code>getInitialState</code> and uses mixin M that also declares <code>getInitialState</code>, will both be merged in the "final" component A ?</p>
  
  <p>Use case : I have several forms which share fields and associated state, and I want to avoid code duplication between them, so that each component declares only what's specific to it. I already used mixins in the recent past, but never with state.</p>