These routines delete the character under the cursor; all
characters to the right of the cursor on the same line are moved to
the left one position and the last character on the line is filled
with a blank. The cursor position does not change (after moving to
y, x, if specified). (This does not imply use of the
hardware delete character feature.)
These functions are described in the XSI Curses standard, Issue 4.
The standard specifies that they return ERR on failure, but
specifies no error conditions.