rebase: use "rebase.collapse" as "editform" for "--collapse" always
Before this patch, if both "--message" and "--collapse" are specified
for "hg rebase", "rebaes.normal" is used as "editform" unexpectedly.
Unlike patches before and after in this series for improvement, this
is bug fix patch.
basic test for hg debugrebuildstate
$ hg init repo
$ cd repo
$ touch foo bar
$ hg ci -Am 'add foo bar'
adding bar
adding foo
$ touch baz
$ hg add baz
$ hg rm bar
$ hg debugrebuildstate
state dump after
$ hg debugstate --nodates | sort
n 644 -1 bar
n 644 -1 foo
status
$ hg st -A
! bar
? baz
C foo
$ cd ..