Release targets:
0.0.5 release:
- remove the "hidden-prepared" layers

Short overview what I want to change in the next time.

Overall:
- cleanup the nameing conventions (and namespace usage ...)
- change all source and destination into src and dest ...
- locking !!
- change .emit to operator () for all signals

WavePlot:
- get the dynamic_cast in the Tracer template to work!!
- implement recycling
- maybe some kind of peak-file usage?

IO:
- keep care that the MixerSources tracks keep in sync on end-limit change

- cleanup ALSAMixerNode::Loop and fix sync during start and stop (capture
  write whole buffer)

- improve EnhTrackVIew:
	- cache markers and selections
	- add better caching of to-refresh-regions (not only one -> array ??)
Other:
- add a global cache (like GIMP tile cache)