OK, four years later, and I still think I need symbol tree. So, this is the patch against the latest svn head.
I build it under 32bit gcc 7.2 under Windows with wx 3.1.1.
I think we can "disable" the option to show the whole project's tokens in the tree, because this should take too long. But for tokens in a single source file, it should be OK. I don't see time lags.