feat(server): Added semi-support for Server Side Rendering

We now have support (kind of) for SSR, in which case we disable the rendering of the placeholders
and send through null values for width/height to the wrapped components.  Read the docs and tread
carefully.

README.md

@@ -15,7 +15,7 @@
 * Extensive browser support.
 * Supports any Component type, i.e. stateless/class.
 * Works with React 0.14.x and 15.x.x.
-* 7.67KB gzipped standalone, even smaller if bundled into your own project.
+* 7.67KB gzipped standalone, even smaller if bundled with your assets.
 
 
 ## Index