v3.0.0-alpha-10

This is a test build not intended for public use.

• Fix mix-up of runtime paths for ZIP file import and environment building. Stdio was re-directed to the same files.
• Change layout of environment building directory to one directory per plan.
• Windows: Avoid permission issues when building environments as non-privileged user.
• Specify only base runtime directory in external configuration.
• Set explicit directory ownerships during directory setup.