[PD] documenting messages to/from Pd and dynamic patching

[João Pais]

>> but I've been using them for more than 15 years with no big issues.
> Well, a few years ago Miller changed the [donecanvasdialog( message. I 
> noticed that it will break dynamic patching and asked him to use a 
> workaround. He was nice enough to do it. So you were just lucky ;-)
>
> Note that the messages found in Pd patch files, like [obj ...(, are 
> pretty stable. We can't really change them without breaking literally 
> all existing patches. However, anything else should really be 
> considered private. Particularly mnssages like [mouse(, [mouseup(, 
> [donecanvasdialog( are obviously internal messages sent between Pd 
> core and the GUI process. People just discovered them in the source 
> code (or by watching the GUI/Pd traffic) and started (ab)using them 
> for dynamic patching. The Pd extended folks included them in their 
> documentation, so usage became more wide-spread. However, it was never 
> officially supported in Pd vanilla.
>
yes, at some point it would be good to assume that they can stay and 
keep being abused (I forgot why they are "illegal"), and when possible 
new methods should come out to replace them.