Ghost Pour Prevention/Detection

[zaepho]

Ghost Pours can occur for various reasons in a flow meter setup. This should be detected and if possible prevented.

See:
https://www.homebrewtalk.com/forum/threads/version-2-release-raspberrypints-digital-taplist-solution.487694/page-87#post-8266777
https://www.homebrewtalk.com/forum/threads/version-2-release-raspberrypints-digital-taplist-solution.487694/page-35#post-7127260