tests/test-diff-newlines.t

merge: use separate lists for each action type

This replaces the grand unified action list that had multiple action types as
tuples in one big list. That list was iterated multiple times just to find
actions of a specific type. This data model also made some code more
convoluted than necessary.

Instead we now store actions as a tuple of lists. Using multiple lists gives a
bit of cut'n'pasted code but also enables other optimizations.

This patch uses 'if True:' to preserve indentations and help reviewing. It also
limits the number of conflicts with other pending patches. It can trivially be
cleaned up later.

  $ hg init

  $ python -c 'file("a", "wb").write("confuse str.splitlines\nembedded\rnewline\n")'
  $ hg ci -Ama -d '1 0'
  adding a

  $ echo clean diff >> a
  $ hg ci -mb -d '2 0'

  $ hg diff -r0 -r1
  diff -r 107ba6f817b5 -r 310ce7989cdc a
  --- a/a	Thu Jan 01 00:00:01 1970 +0000
  +++ b/a	Thu Jan 01 00:00:02 1970 +0000
  @@ -1,2 +1,3 @@
   confuse str.splitlines
   embedded\r (no-eol) (esc)
  newline
  +clean diff