Possiblity to add default permissions and to add permission value none

[mniehren]

I would like to setup the default permissions of an public folder to deny. To do that,
2 things are currently missing:

• add an default permission to an folder:
  grommunio-admin exmdb domain folder grant folderid default value
• set permission none to an folder
  grommunio-admin exmdb domain folder grant folderid default none

The command should end in the following entry in the exchange.sqlite of the domain
INSERT INTO permissions VALUES(13,427681,'default',0);

Currently a value of "0x0" is switched to all (0x27ff)