FIX: hash::Ramdomize() with optional seed or Prng
TEST: T_CatalogTraversal.ZeroLevelHistoryTraversal
rename MightPush() to Push()
directly track is_root of MockCatalog
FIX: MockCatalog::Clone()
FIX: initialization of RNG in MockCatalog
add doc of catalog count in MockCatalog revision
FIX: initialize global test state
TEST: add simple test cases for history traversal
add CatalogTraversalParams::kFullHistory const
TEST: T_CatalogTraversal.FullHistoryTraversal
no_repeat_history optimization
update doc of CatalogTraversalParams
rename Push() to MightPush()
TEST: T_CatalogTraversal.FullHistoryTraversalNoRepeat
TEST: T_CatalogTraversal.SecondLevelHistoryTraversalNoRepeat
FIX: typo