hbase-4238 CatalogJanitor can clear a daughter that split before processing its parent
Review Request #1819 - Created Sept. 13, 2011 and updated
Previous, we'd not clean up a parent if its daughter region didn't exist in the fs. This stipulation was added by HBASE-3872. This patch undoes this barrier to parent cleanup (See HBASE-3872 for why its ok to do this). CatalogJanitor + Break out the Comparator used by CatalogJanitor. It was an anonymous class. Instead we make it a static inner class so can add test that its actually sorting properly. + Added method hasNoReferences that will return true if no daughter dir OR no refs in daughter dir Added some TODOs around SplitTransaction -- vaguely related to this patch. Added new Test that checks cleanParent to ensure it works properly. Refactored bits of previous tests so they use common code.