%N bug %F $MIR/src/subs/bug.c
%D Issue an error message, given by the caller.
%P pjt
%: error-handling
%B
FORTRAN call sequence:
        subroutine bug(severity,message)

        implicit none
        character severity*1
        character message*(*)

  Output the error message given by the caller, and abort if needed.

  Input:
    severity    Error severity. Can be one of 'i', 'w', 'e' or 'f'
                for "informational", "warning", "error", or "fatal"
    message     The error message text.                                 
