MVStore: use a mark & sweep GC algorithm instead of reference counting, to ensure used chunks are never overwrite, even if the reference counting algorithm does not work properly.

git-svn-id: http://h2database.googlecode.com/svn/trunk@5947 e6896862-9d19-0410-bfb3-e9fa5d50e656
MVStore: use a mark & sweep GC algorithm instead of reference counting, to ensure used chunks are never overwrite, even if the reference counting algorithm does not work properly.

git-svn-id: http://h2database.googlecode.com/svn/trunk@5948 e6896862-9d19-0410-bfb3-e9fa5d50e656