Permissions should be customizable by role

[Xetera]

Users should have the ability to customize the permissions of commands based on roles.

• The ability to do this should be based off MANAGE_ROLES
• Moderators should not be able to reassign a command that requires higher permissions than they have to something else even if the have MANAGE_ROLES
• Moderators should not be able to assign a command a role that is higher than their current highest.
• When a role delete event is fired, the custom permissions for the current guild should be checked. If it matches any, the entry should be removed and should fall back to the default ones I've assigned.
• The crosscheck should also take place on startup to make sure we haven't missed any deleted roles during downtime.