Permissions API

Permissions/Groups API specification, minecraft/forge patches and default implementation by me and @AbrarSyed
Framework = mod implementing PermBuilder and PermBuilderFactory
As I have said, the levels are just DEFAULTS to assist the framework in sorting commands based on permission level. If I make it node-only, how is the implementation supposed to sort the commands based on access level? The whole point is that frameworks are allowed to manipulate the node, to change between access levels, to allow "power user" and such not-op groups to exist. This is already the same as if modders implemented getRequiredPermissionLevel, and personally, I do not think it has a large effect on the framework or the mod registering commands.