fix for vmware VMs

[iddq]

ttybus/tty_attach.c

Line 100 in 32e9a9e

realdev = open(devname, O_RDWR);

-       realdev = open(devname, O_RDWR);
+       realdev = open(devname, O_RDWR|O_NOCTTY|O_NONBLOCK);

[danielinux]

tty's may be used as controlling TTY in some cases, so O_NOCTTY by default is not an option.
I don't see any valid reasons to make the socket non blocking either.

Perhaps both could be configuration options if it makes sense.