Subbosses authenticate to the XML-RPC server as elabman, which means the
resulting server process runs as the elabman user.  Unfortunately, this
doesn't work well when the subboss wants to launch a frisbeed for an
image for which elabman doesn't have read permission (like images under
/proj).

To fix this, a setuid wrapper script is run instead of trying to run
frisbeelauncher directly.  This script makes sure the calling user is
elabman, and then becomes root and execs frisbee_launcher.