(random_init_user): New function. Replaces make_user_random. Tries
to create the seed file if it is missing.

* src/unix_random.c: Use globals for the generator state.
(unix_random): Deleted class.
(read_initial_seed_file): Simplified. Permission check moved to
random_init. Seeking is done by read_seed_file.
(update_seed_file): Deleted argument. Use seed_file.h interface.
(trivia_source): Renamed from do_trivia_source. Use globals.
(device_source): Renamed from do_device_source. Use globals.
(random_generate): Replaces method do_unix_random.
(random_add): Replaces method do_unix_random_add.
(random_init): Use seed_file.h interface. Initialize all globals,
including the sources'.
(make_user_random): Deleted, replaced by random_init_user in
unix_random_user.c.
(random_init_system): Replaces make_system_random.
(lsh_random): Moved definition here, from randomness.c.

Rev: src/unix_random.c:1.20
Rev: src/unix_random_user.c:1.1