Added testcases in ObjectDatabase for embedder Map<String,Object> read-write
alpha commit
Added schema synchronize in ObjectDatabase:
1) changed OMetadata as interface
2) added OMetadataDefault implementation (old OMetadata class)
3) created OObjectMetadata and OOBjectSchemaProxy as wrappers
4) moved schema object management in OObjectSchemaProxy class
5) added schema synchronizing (creates schema and classes of registered entities if non existent)
Renamed ObjectMetadata and ObjectSchema class names
Merge branch 'develop' of github.com:/orientechnologies/orientdb into develop
Merge branch 'ObjectSchema' into develop