Modified TestSuite setup to properly start/close MongoDB only once, per Suite execution
Changed license header to correctly reflect cherimojava license
Added basic EntitySchemaProperties containg entity properties
Added Id saving component
_v and _h fieldnames are reserved to VersionedEntities
Save only happens if entity was changed; version information is always present for VersionedEntity
Save returns if the entity was saved or not, as saving only happens if there was a change on the entity