Add support for tuples in def_data.in; these are implemented as an

Add support for tuples in def_data.in; these are implemented as an
enum type.  Currently there is only a single tuple enum but in the
future we may have one tuple enum per T_TUPLE entry in def_data.in.
Currently listpw, verifypw and lecture are tuples.  This avoids the
need to have two entries (one ival, one str) for pwflags and syslog
values.

lecture is now a tuple with the following values: never, once, always

We no longer use both an int and string entry for syslog facilities
and priorities.  Instead, there are logfac2str() and logpri2str()
functions that get used when we need to print the string values.