v0.4.0

Changes in v0.4.0:

• [Feature] Command-line: airup start --cache and airup stop --uncache
• [Feature] airup self-reload CLI utility
• [Feature] stdio setup
• [Feature] API: system.is_booting and info.build_manifest
• [Feature] Better ACE
• [Feature] Supervisor timestamp
• [BREAKING] Environment variables: AIRUP_SOCK, AIRUP_SERVICE, AIRUP_SERVICE_MAINPID
• [BREAKING] Deprecate policy model
• [Fix] Deadlock with forking
• [Fix] Corrupt StopService failure condition
• Performance optimizations