Renamed OFlattenIterator in OMultiCollectionIterator allowing generic types
Fixed issue #1389 about concurrency problems on Pool.acquire()
Minor: added asserts in test case
Update path of OrientBatchGraph after BP refactoring
Get record metadata support for binary protocol was added.
SQL: "group by" now supports context variables
Merge branch 'master' of https://github.com/nuvolabase/orientdb
Minor: removed warning about Unsafe usage
MMAP was drop for hash index and new disk buffer was added.
Local hash table abstraction was added.
Iteration functions were added into hash table.
Local hash table test was added.
Local hash table tests were added.
Iteration  tests were added in local hash table.
OPLA: Supported nullAsEmpty in OutputBlock
Merge branch 'master' of https://github.com/nuvolabase/orientdb
Merge pull request #1 from nuvolabase/master

update from nuvolabase repo
OPLA: fixed debug messages
FIxed issue #1294 and in Studio, integrated UML class diagram through YUML
Merge pull request #2 from nuvolabase/master

update from nuvolabase repo