Fix related changes after rebase

Given a stack of two commits C->P (child depends on parent), if P is
rebased or updated C should still considered to be a related change,
even if C has not yet been rebased onto P' (new P).

This was broken because we did not include all permutations of P
into the seed queue.

Bug: issue 2073
Change-Id: Ife954810ece39f44630b8c17a4f1b70192bd1611
Write a change message when approvals are removed

If the approvals of a reviewer are removed (e.g. by the project owner)
this is now recorded as a change message so that it later can be seen
who removed the approvals.

This change only affects removing reviewers on ChangeScreen2. If a
reviewer is removed on the old change screen there is still no
message.

Bug: issue 1300
Change-Id: Ibe95d1835e065d6c142edbf53e2ce483c4dc4889
Signed-off-by: Edwin Kempin <edwin.kempin@sap.com>
Merge branch 'stable-2.8'

* stable-2.8:
  Fix related changes after rebase
Merge "Write a change message when approvals are removed"