Mg v4.3

Changes

• New delete-selection-mode: typing, yanking, or inserting a newline
  with the mark active replaces the region, and C-d or DEL deletes it.
  The region is not killed. Enabled by default, like visual-mark-mode
• C-SPC C-SPC sets the mark without activating it, for the mark used
  as a place to return to with C-x C-x
• C-Home and C-End move to the beginning and end of the buffer
• New ido-mode: the M-x, buffer and file prompts match what is typed
  as a substring and show the matches on the echo line, the selected one
  in bold. RET picks it, the left and right arrow keys, or C-s and
  C-r, step through the matches, TAB completes what they have in
  common, C-j takes the text as typed and C-f at the end of the text
  falls back to plain completion. At a file prompt the directory is
  part of the prompt: RET enters a subdirectory, DEL with nothing typed
  goes up, ~/ and // jump to the home directory and the root, and
  C-d with nothing typed opens the directory in dired. Enabled by
  default, ido-mode 0 in ~/.mg disables it

Fixes

• Fix C-d and DEL leaving the deleted text in the kill ring when it
  was empty, so the next C-y brought it back