Almost all terminals now support hardware tabs so default to OXTABS
off.
This makes three changes: adds the ht capability to the standard lines
in gettytab(5); removes OXTABS from TTYDEF_OFLAG in ttydefaults.h (the
defaults used by pty(4) - diff from martijn); and only sets OXTABS on
terminals which lack hts and tbc in tset(1) (from Thomas Dickey
upstream).
Addresses problems reported by tedu.
ok millert