window: redefine special key values

doc/bindings

@@ -51,8 +51,9 @@
 ##      picked by ncmpcpp upon next call to readKey function.
 ##      Accepted values: mouse, up, down, page_up, page_down,
 ##      home, end, space, enter, insert, delete, left, right,
-##      tab, shift_tab, ctrl_a, ctrl_b, ..., ctrl_z, f1, f2,
-##      ..., f12, backspace, backspace_2.
+##      tab, shift_tab, ctrl_a, ctrl_b, ..., ctrl_z, ctrl_[,
+##      ctrl_\\, ctrl_], ctrl_^, ctrl__, f1, f2, ..., f12,
+##      backspace.
 ##
 ##    - push_characters "string" - pushes given string into
 ##      input queue.
@@ -111,12 +112,6 @@
 ##    could be used. Then ncmpcpp will not wait for confirmation
 ##    (enter) and will execute the command the moment it sees it.
 ##
-## Note: Both 'backspace' and 'backspace_2' are used because some
-##       terminals interpret backspace using keycode of 'backspace'
-##       and some the one of 'backspace_2'. You can get away with
-##       binding once if all your terminal emulators use the same
-##       value.
-##
 ## Note: There is a difference between:
 ##
 ##         def_key "key"
@@ -294,12 +289,6 @@
 #def_key "backspace"
 #  replay_song
 #
-#def_key "backspace_2"
-#  jump_to_parent_directory
-#
-#def_key "backspace_2"
-#  replay_song
-#
 #def_key "f"
 #  seek_forward
 #