Use execas to exec redis in upstart.
Revert "Revert "Add daemontools 0.76.""

This reverts commit aad4e9679af90affe97fc89a30866b25f84708d7.
Fix error for uninstalling when svscan is stopped.
Use setuidgid to execute redis in upstart.
Remove execas. Use setuidgid in daemontools instead.