Battlefield roles: Add some of "Light" role

[Goosius1]

DESCRIPTION

• This PR partially adds a new feature called "Battlefield Roles", which is part of a wider solution to open up combat to "Regular" players, instead of just "PVP elites".
• This solution comes at a critical time for Towny/Minecraft (IMO). as PVP combat has become so well-developed by the playerbase in recent years, that large numbers of players and potential players can no longer participate in meaningful combat, due to the need for excessive grinding for gear & potions, and extensive training.
• The Battlefield Roles feature is very simple to use - each player just picks their battlefield role:
  • Light: Lightly armoured and fast. Good for scouting and skirmishing. A good pick for combat-newbies.
  • Medium: Moderately armoured and powerful. Good for versality, melee charges and anti-cavalry. A good pick for top PVP'ers.
  • Heavy: Heavily armoured and slow: Good for holding ground. A good pick for experienced PVP'ers, as long as they can acquire the expensive armour.
• This PR implements some of the feature, as follows:
  • Config nodes
  • Permission nodes
  • Lang string additions
  • Command to change role
  • Persistance of role change in metadata
  • Viewing the light role on the Resident screen
  • Armour restriction for light role
  • Weapon restriction for light role
• Future PR's will add the remaininder of the light role, and the other roles
• The first release of this feature will include light/heavy/medium, but probably not medic or engineer
• This feature will replace the "Encumbrance" feature, which is simply a less fun and less usable alternative, then the Encumbrance feature will be deleted

ASSOCIATED TICKETS
Closes #46
Closes #58
Closes #64
Closes #69