Pyblish-standalone exit prematurely

Support
#21

Aw, ouch! I didn’t know this was such an issue for you guys.

Running one instance of qml per host is trivial, it just hasn’t been requested before. Feel free to submit a feature or pull request and we can get started asap.

#22

Have created an issue with a reproducible test; https://github.com/pyblish/pyblish-qml/issues/212