3.2.1 b536

Changes by @stumper66:

• fixed having min-player-level or max-player-level with a value of -1 causes the drop to never occur
• fixed shooting a mob with a bow or hurting with splash potions never causes the nametag cooldown to be triggered
• fixed setting player-levelling-relevel-min-time to 0 in settings.yml breaks player levelling
• shortened player levelling debug messages and included level cap if applicable
• running /lm rules force_all will also cause player levelling to be re-evaluated
• fixed PAPI placeholders %levelledmobs_level% and %levelledmobs_displayname% causing exceptions
• renamed %levelledmobs_level% to %levelledmobs_mob-lvl%
• %levelledmobs_mob-lvl% and %levelledmobs_displayname% will be from either the last mob to kill the player or last mob the player killed
• in custom drops both itemflags and item_flags are valid value names but the later is preferred
• item_flags can be used as an array list or a string with semi-colon separated items