[C] Add client shared library

[kdoherty2]

No description provided.

[tmontgomery]

What does the TLS error handling do? The API at this point does not use this style of error handling. So, why is it added?

Also, the naming conflicts with C native driver naming making bringing in an embedded native driver problematic.

Thirdly, what is the motivation for this PR? The client is quite small. What does making it a shared object help with?

Fourth, why export all symbols? This is less than ideal on Windows. Why do this?

[kdoherty2]

re: the motivation
The customer application uses aeron through an intermediary non-latency critical layer which links dynamically

[skurkchan]

re: TLS error handling
I can remove DLLMain then. Is that OK ?
Or keep the function and remove error handling ?
Thanks.

[tmontgomery]

The DllMain and associated error functions are not needed in the client. And as I point out, could conflict if the C driver is used with the client.

[mjpt777]

How where the set of classes decided that CLIENT_EXPORT got added to?