Yet another alert accessory (PD).
improvements:
- runs with SingleAES (here with or without MiNTnp) or MultiAES
- cares for the close-on-exec-flag under SingleAES
- includes a nohog.acc (important for MiNTNet), example:

accessory   ping time under GEM 3.1 (single)
--------------------------------------------
none        infinity
TOS screen  10 ms
nohog       60 ms
KGMD alert  195..235 ms
this alert  30..119 ms (average: 70 ms)

Alert runs only as accessory.

UK 06/30/1996
