Remove view permissions from a permission-less Role

[ssddanbrown]

At the moment a role with no permissions still has view permissions (Since there are no view permissions currently on a role level). Adding view permission control to roles will allow you to have very 'unprivileged' roles which then you can 'whitelist' on specific assets to allow very controlled access.

This is a spin off from the changes in issue #89.

[ssddanbrown]

Removed this from being targeted in the next release. Realised that some major work needs to be done to re-write the permission system to be more maintainable and flexible.

Currently the role permission and entity permissions cannot easily be queried together and are checked with code. I want to combine these permissions into some kind of 'permission reference' table for faster and simpler querying.

[ssddanbrown]

Now complete with new permission system, Will be in next release.