character_delete_right

 This deletes the character after the cursor.

 If we are at the end of a line it attempts to join the current line with the
 next line. If the line after is not a text line, it cannot be joined with
 the current line.

 The character is not lost forever, as it is put on the deleted item stack
 maintained by the editor. Items on this stack may be recovered using
 other_undelete and other_put.