Added Linux build support.

[TylerJaacks]

No description provided.

[rauhul]

Thank you for the contribution @TylerJaacks, it looks like you still have a number of TODOs/FIXMEs left resolve before this is ready to be reviewed. Is that correct?

[TylerJaacks]

Yes but I thought I would bring in a pull request to see if this could even be merged? If so I will continue to fix my TODOs if not I can just maintain this by myself. Thank you.

[rauhul]

Adding linux support is definitely something I'm happy to add to this repo!

[TylerJaacks]

So the main issue here is that

I have no idea what is going on with these

-Wl,-exported_symbol,_eventHandlerShim \
-Wl,-exported_symbol,_eventHandler \

I'm not sure why they are here, building on Linux with these result in _eventHandlerShim file not being found and _eventHandler not being found. If I remove these on Linux it builds fine. I have tested them on my device, I have not tested them on the Simulator cause it is annoying to get setup in WSL, so I will have to install a Ubuntu VM.

I was hoping you would be able to help me figure this out.

In regards to the other TODOS they aren't mission critical I just don't like the names I chose the variables in the code and what I am using for environment variables.

Finally I think it would need to be tested to see if this still builds on macOS, I guess I will have to dig out my MacBook Pro and test.