Use a POD for the format body. This allows us to more easily build
and copy the formats.
Remove obsolete code to make video and audio formats.
Use SpaVideo/AudioInfo to keep track of formats. Make functions to parse
the format into the structures.
Update plugins
POD (plain old data) objects are similar to LV2 Atoms and allows storage
and construction of datastructures in memory or on the stack. They can
be copied with a simple memcpy.
The idea is to use this to construct the network messages and to replace
the structures used for describing formats and properties.
