Some comments added to MetaInformationTable.java

Signed-off-by: SergeyKrivohatskiy <s.krivohatskiy@gmail.com>
Deleted flag added to TableBase. Index may be used now without reindexing on delete.
'vacuum' method isn't implemented

Signed-off-by: SergeyKrivohatskiy <s.krivohatskiy@gmail.com>