Yocto support

[vmartinlac]

Hello, Yocto is a collection of tools for building Linux distributions. It is primarily intended for embedded platforms (although it can generate a complete Linux based desktop operating system) and is highly customizable. In order to integrate a piece of software into Yocto, one must write a recipe. This is the description of how to build it. ROS provides such recipes. It would be nice if Yarp provided official Yocto recipes.