Cleaned up and improved the audio tab.
Fixes#1546. Kind of. There doesn't seem to be much need for a
sample rate selection for our current high-level audio system.
If we implement higher end audio backends in the future (e.g.
ASIO, JACK), those can be given a sample rate setting.
Project items are now represented directly in nodes opening up more versatility and possibilities. This is the first iteration of this and will be buggy. Need to test thoroughly.
Olive now has a set of colors that categories can be "assigned" to. The timeline also shares the same colors as the NodeView. Colors can be configured per node (aka per clip).
The macro defined namespaces confused the hell out of lupdate and more or less broke translations permanently. Looks like the only way we can do it is to have a hardcoded namespace, which goes against my instinct, but honestly how likely is it that we'll change the namespace anyway (I guess forks might want to do it, but that's their problem ;) )
Improves Preferences dialog's "accept" speed. Before it would try changing the
style no matter what which took a noticeable amount of time to do for no real
purpose if the style didn't change.