Store where Processing is installed by Stefterv · Pull Request #1022 · processing/processing4

It has been clear to me for a while that third-party tools need a way to discover where Processing is installed.

The Java Preferences are not the best solution but they are the best documented and clear on how this would work and is a tool that we won't have to maintain.

• Add some documentation to the repo on how to read the Java preferences outside of Java
• Remove old install locations
• Remove duplicate install locations because version changed