module Errors:sig
..end
handle f
runs f
and exits with exit status 0.
If f
raises an error exception, a error message is printed
and we quit the program with exit status 1.val handle : ?dont_exit:bool -> (unit -> unit) -> unit
val set_error_channel : Pervasives.out_channel -> unit
set_error_channel c
defines the channel into which we print
the error messages.