Add the fd to the SpaData so that we can noth use the fd and the mmapped
memory when we want instead of needing to mmap again in the plugin.
various cleanups
Remove the memory stuff from the spa API, we can do thing more simple
and efficiently if we always allocate buffers outside of the plugins and
only implement an alloc function on the node when it can do something
clever.
Move serialize code to the props/format/buffer code
Make it possible to copy a format and properties.
Reserve 0,0 for stack allocated mem that we never free
Improve allocation in the link
Parse format and properties in-line, there is no need to allocate
memory.
Improve buffer cleanup in alsa
Add timestamps and offset to alsa
