[LV2] Request: Can-Randomize control hint

[Filipe Coelho]

Hi there, I have a request for LV2.

I'm currently implementing a randomize option for plugin parameters in 
my host, and realized some params should never be changed this way (like 
volume).
I can lookup port designations and leave volume and a few others out, 
but it doesn't sound like a perfect solution.

So, what do you think about adding a new port property for this?

Something like:
http://lv2plug.in/ns/ext/port-props#canRandomize