Give more control over snapshot permission

Descriptive title for this enhancement

Have the possibility to restrain the snapshot permission in another way than only reading / writing all in ACL.

Actual behavior

Actually the user need the right to read and write overall in the branch to make / restore a snapshot. It's ok when the user have full rights on the branch but it doesn't work in restrain rights. Example if a user may edit only some fields in a branch but want use snapshot.

Expected behavior

Have a better way to let a users make snapshot and restore them.

Step by step description of new behaviour

Give right to only make and restore snapshot without looking at the permission of the user.