"add-to-path" message to Pd & "cyclone solution"

Pd 0.48-0 has a new message that allows us to add things to Pd's search path, see https://github.com/pure-data/pure-data/commit/c917dd1938e8b48927dc6414916bdc47bbcfeb34 I would consider this a bug as Purr Data says it uses 0.48. Now, you might wanna hold this update, as there is still a consistency error popping up, nonetheless, I'd like to have this highlighted.

By the way, current GEM uses this and Cyclone is about to use it to automatically add cyclone's path. This will allow libdir_loader to add cyclone as a library and also add it to the path, which was a problem we were having. This is the perfect solution, as it makes cyclone's installation as we wanted and it doesn't require changes to libdir_loader, etc.

Actually, old GEM in Purr Data already does this, but in an old way. So you can load objects like [gemmouse], which is an abstraction, because GEM's path gets added when the library is loaded via libloader! Hence, if the new way doesn't come soon for Purr Data, we can also do this the old way for the sake of including cyclone.

cheers