This makes the node system somewhat more high-level with the intent of making
working with them far more flexible and stable. By making the architecture more
abstracted, it becomes far less rigid which should allow us to do even more
with it and make it much less crash prone.
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 ;) )
Since rationals aren't a known Qt format, the QVariant container can't
automatically convert them to and from strings (for XML serialization). We have
to hijack these functions and do the conversion manually for those types.
Also moved the block name type to a node input, which means it's serialized
and copied by default (I'm not sure why it wasn't already like this).
Since the nodes won't be holding any rendering data themselves in this system,
we may as well enforce some level of non-write access by setting all the
functions to const. They were already const-friendly, they just weren't
labelled as such.
itsmattkc