Adoption of the OrientDB plocal engine instead of the local one

The plocal engine should be more durable than the local one.
This should prevent the indices corruption that sometimes happens when the
BaasBox process is killed.

To migrate from previous version of baasbox, the administrator must
perform a backup (via console) on the older version and then perform a
restore on the new one.
Merge pull request #9 from baasbox/master

update from origin repo
Performance improvements

Removed the unncessary overhead of creating edge between documents and
users and collection objects as well.
Merge pull request #93 from giastfader/master

Performance improvements
Merge pull request #14 from baasbox/master

pull request from repository baasbox