Implement failure handling in datum_coinbaser_init.

[jesterhodl]

No description provided.

[luke-jr]

Probably should kill the entire process, not just log

[jesterhodl]

Probably should kill the entire process, not just log

It will exit, because the caller of datum_coinbaser_init() is in datum_gateway.c and does exit(1):

        if (datum_coinbaser_init()) {
                DLOG_FATAL("Error initializing coinbaser thread");
                usleep(100000);
                exit(1);
        }

Or do you want to exit right away in datum_coinbaser_init() in datum_coinbaser.c?

[luke-jr]

This was merged...