The pointer could go out of bounds when decremented if it was pointing
at the start of the status_vals[BL_HUNGER] (empty string).
Also, guard tty_status_update() from an out of range index being
passed to it (botl shouldn't do that, but...).
The legal 1st parameter values for tty_status_update() in 3.6.2 are
BL_RESET (-2)
BL_FLUSH (-1)
BL_TITLE ( 0)
...though to...
BL_CONDITION (22)
count MAXBLSTATS = (BL_CONDITION + 1)
There's a BL_CHARACTERISTIC (-3) defined in the botl.h header file,
but it is not used in wintty.c and is now screened out along with
everything lower and everything MAXBLSTATS and above.
closes#142fixes#141
c5d0f6dd9d