RFE: export enums

[SpareSimian]

I'm planning to use enums for my application commands. It would be nice if export_types.py could handle those. I'll see if I can figure out how to add this. (My app will be in C++ so I'll also write a new version that outputs C++ declarations.)

[SpareSimian]

I found I needed to add a ", True" to the call to projects.primary.find to recurse down the project tree for my types defined under ./Device/PLCLogic/Application.

I wanted to use SMC_ERROR in my AppFbk struct but it's defined in a library, so projects.primary.find() doesn't find it. I'm not sure what's necessary to extract it to export it.

[SpareSimian]

I found this promising snippet for descending into the app's libraries. I'm investigating to see if I can get at their symbol definitions.
https://forge.codesys.com/tol/scripting/snippets/22/

[SpareSimian]

A work in progress. https://gist.github.com/SpareSimian/980944221f3f04b1e2758ed02a6c16bd

This handles enums. I might make it preserve comments.

I haven't found a way to get at the symbols defined in libraries, so I'll probably have to extract those from web pages and create my own C++ headers for them.