The bitArray.IsSequence method had a bug that caused that sometimes the
test "Bitmask/IsSequence/sequence starts at other index than 0" to fail
due to it uses random values.
The test mostly found a corner case, I've added new tests to catch the
bug and then apply the fix.
Change-Id: If01dc07006d261ba40bbd99d36ef776e09ed3efc
Change the bitmask used by segment reaper to use []byte rather than uint64
This passes tests but I have literally no clue how to integration test this.
Change-Id: I393f4598b27cae6e427da2190dd3109bca721c34