v4.1.3 b68

• fix potential error when using 3rd party custom drops air cannot be serialized
• fix %location% populating with XXZ instead of XYZ
• have worldguard regions condition use a cache instead of calling WG API each time
• fix rare issue of not all rules getting applied to a mob in certain situations
• add support for custom drops extras using formulas
• update bstats to 3.1.0
• update PlaceHolderAPI to 2.11.6
• update item-nbt-api-plugin to 2.13.1
• fix player variable mod scale not working with values less than 1
• fix %rand% in construct-level actually generating a max number one less than specified
• fix player variable mod tiers not getting parsed correctly
• add internal placeholders %min-level% and %max-level%
• fix nbt-data not working on items
• update nbt-data methods to use the latest API functions which should be more performant