Timed sell limit

[pmakin]

Configurable sell limit correlated to local time.

If player has permission, he will be checked for it's limit

Config prototype:

sell-limits:
    -   permission: fastsell.limits.low
        period: 5 
        period-unit: hours
        limit: 600
    -   permission: fastsell.limits.mid
        period: 15
        period-unit: minutes
        limit: 5000
    -   permission: fastsell.limits.high
        period: 7
        period-unit: days
        limit: 15000

Messages:

limit-exceeded: You exceeded your sell limit by {exceeded}. You are currently at {player_limit}/{total_limit}.