These globals were used to store the original terminal dimesions from the terminal database (or
in the case of reattaching, supplied by scr-bx) to be applied if the current terminal dimensions
could not be determined.
Instead, we leave the original terminal dimensions in current_term->TI_lines and current_term->TI_cols,
and create current_term->li and current_term->co to store the current terminal dimensions (as eg.
supplied by scr-bx).