JX_LoopOnce() hangs if process.exit() has been called previously.

[enricogior]

When JXcore is embedded, the caller typically calls JX_StartEngine() followed by JX_LoopOnce() or JX_Loop().
JX_StartEngine invokes engine->loopOnce() causing the subsequent call to JX_LoopOnce to hang if process.exit() has been processed in the first loop.
A possible fix is to remove engine->loopOnce() in JX_StartEngine or add a new API in order to avoid breaking changes.
The ideal fix would be to have JX_Loop() return and not hang when the libuv loop has already been terminated.

[enricogior]

Currently using a workaround: we keep track if process.exit() has been called and if true we don't call the libuv loop.

[yaronyg]

@enricogior Given that we have a work around can we move this to back log?

[enricogior]

@yaronyg sure.