SA-master todos

[sshane]

Todo list for https://github.com/sshane/openpilot/tree/SA-master

• Allow comments in files_release
• Build release branch?
• Model MPC for e2e button?
• Do UI
• Remove custom longitudinal delay code, use the one in stock!
• Ensure dirty stays stock, but create sa_dirty or similar for personal Sentry
• Clean up added controlsd code
• Clean up changes around openpilot now in stock
• Revert longcontrol and PID to stock and rethink/retune
• Make sure camera_offset is correct for C3
• Fix version in title bar