Peerplays Alpha release 1.5.20-alpha

This is a release branch based on the features currently in active development.
Major features in progress are:

Improvements to SONs
Ethereum SONs preview
Numerous bug fixes and improvements

Who should be using this release ?
dApp teams and anyone interested in getting access to the new features.
All dApp teams are requested to use TESTNETs based on 1.5.20-alpa