Development guide

Added guides for developing code and/or documentation.
I think of HVA as running on a host. i.e. the host is the hardware (or virtual hardware).  Collector above is described as a "process".  "is the part of Wakame-vdc" --> "is the Wakame-vdc process"  ??  The word "node" is vague and should either be defined the way we are using it in the Jargon or avoided.