Fixed requirements.

Change-Id: Id776a6a8217c31643f1a98403a6f3dd3a5727554
Don't store the private key in the db.

Metadata update requires re-creation of server.

Change-Id: I16c6640cee86534127a8ccf0b9d2e79bdb5b62c4
Rework exceptions.

Change-Id: I76462e4fb0dec52d5e13bde061aec5d2c1a3d129