parameter that controls whether or not certain characters in the
string are interpreted or not (things like tab being expanded).
Make __waddbytes a wrapper for _cursesi_waddbytes that passes all
parameters and sets the flag for character interpretation for backward
compatibility.
Fix an incipient bug in _cursesi_waddbytes where garbage would have
been written to the terminal if the terminal TABSIZE was set > 8 and
character interpretation is on.
Convert all internal __waddbytes calls to use _cursesi_waddbytes, fix
the function prototypes and add a new flag that will be used later.
Fix the addchstr family functions so that they call _cursesi_waddbytes
with character interpretation off as per SUSV2.
