When compiling a stand-alone version of the library, the properties of `ShapeOptions` need to be included as externs for the compiler.  The way we handle this currently is to add blocks to the `objectliterals.jsdoc` files and use the `olx` namespace (see the [`olx.style.CricleOptions`](https://github.com/openlayers/ol3/blob/f9a9f70a4389e8375f991aa566cb4960cc62457f/src/objectliterals.jsdoc#L924) for inspiration).