Create Javadoc hint for Application#start() not returning on lwjgl3

[MeFisto94]

So, since we probably won't be able to fix this problem, at least not relatively short timed, it might be worth to add some knowledge to the wiki (@mitm001) and/or the javadoc for the start() methods.

Specifically on lwjgl2 one can choose: Return immediately or return after the context has been created. On lwjgl3, start() will return when the application has requested to quit (e.g. stop() has been called).

Another problem, I think, is that calling app.stop(true) will deadlock the application on lwjgl3, as it waits for context disposal, but this disposal happens after the update loop, which is locked due to passing true there.

That being said, lwjgl2 has the same problem there, I think.

Edit: The second part is a duplicate of #1257

[Ali-RS]

Specifically on lwjgl2 one can choose: Return immediately or return after the context has been created. On lwjgl3, start() will return when the application has requested to quit (e.g. stop() has been called).

Note, this has been fixed for a while now. Only on Linux and Windows. https://github.com/jMonkeyEngine/jmonkeyengine/pull/1690/files

[stephengold]

In my opinion, the actual fix was here:

https://github.com/jMonkeyEngine/jmonkeyengine/commit/40bb6483601c0aa26ae4f0d77bc965914a24528b

[Ali-RS]

I will update that Javadoc and mention that is only happening on mac os.