Enable/disable commands

[eupedroosouza]

Adds the ability to enable and disable a list via command.

These commands have been added:

/whitelist enable - enable the whitelist
/whitelist disable - disable the whitelist
/blacklist enable - enable the blacklist
/blacklist disable - disable the blacklist

Also added the 'enabled' option in the list configurations (whitelist.yml and blacklist.yml) and removed 'whitelist_enabled' and 'blacklist_enabled' from the main configuration.

[Fallen-Breath]

You changed the config entry layout, which means you need to provide a migration method for this. Nobody wants the configured behavior get changed unexpectedly

Or you can just don't change where the whitelist / blacklist's enabled states are stored. Make it simple, and focus on the enable/disable command

[eupedroosouza]

Ok! I will post a review here!