Why does the plugin hold a context outside of the connected state?

[jonnew]

The act of dragging a plugin into the signal chain will create a context event though, I think, no hardware communication (other than maybe getting device table but no actually using it, is done until the connect button is pressed.

The motivate for this issue is that it feels like when the editor is grey and disconnected that it should not have ownership of an ONI context because it almost by defintion is doing nothing with it. This prevents e.g. another instance of the GUI from operating if somebody tries to add an onix source to its signal chain. Same thing with bonsai.

I think the inactive, disconnected node should not hold an ONI context.

The liboni version can and should be displayed using the macros rather than using the oni_version function.

[bparks13]

Related issue: If we are going through the trouble of reworking the context lifetime, we should also make use of cpponi, especially now that we have the liboni submodule already present in the repo.