uucp break-sending speed

[utzoo!henry]

V7 uucp (actually, uucico) sends BREAK by dropping the speed momentarily
(to the value specified by Bspeed) and transmitting NULs.  The value
of Bspeed is 150 baud, which is reasonable.  BUG:  Bspeed is initialized
to "150", NOT "B150".  Fix:  make the change, in the declaration of
Bspeed in uucpdefs.h.  This introduces one problem:  uucpdefs.h now needs
the system include file sgtty.h (for the definition of B150).  Either
one can run around putting "#include <sgtty.h>" in all six uucp source
files that include uucpdefs.h, or one can put the include in uucpdefs.h
and delete any independent includes of sgtty.h in source files that also
pick up uucpdefs.h (there is only one such, in cico.c).  The former may
be cleaner, the latter is easier.

Thanks to Ron Gomes of Human Computing Resources, who noticed this.