Added pressure_plate_activated.

I can't figure out if there's a way to also detect when the pressure plate is released, but for now this works fine for generally triggering the event when it is originally stepped on.
Reserved the "activated" parameter for pressure_plate_activated.
Updated pom to link to Bukkit 1.5.
Updated MCEntityType with the new Minecart enums.
Improve inventory_click event, add get_entity_age, set_entity_age, add info about groups owners and members to sk_region_info
Merge pull request #95 from MariuszT/pullable

Improve inventory_click event, add get_entity_age, set_entity_age, add info about groups owners and members to sk_region_info
Added "cause" parameter to persistance exceptions to make tracking a bug easier.
Merge branch 'master' of github.com:sk89q/commandhelper.git
Added logic to detect the encoding of a file (and use that) in the PN
Added a conditional, so if a literal null is encoded in json, it won't NPE.

I'm actually not sure about this one, because it apparently depends on the file encoding, even though the contents of the file otherwise don't change.
Added a shortcircut to return null if the object returned is null.
Added an example to set_mob_equipment
Started adding redis to the PN.
Suppressed all exception messages in the Abstraction Enum Verification Thread.

These don't pose any sort of danger for the server, and are simply a nuisance when not in debug mode, so the warning is still shown, but only if the server is in debug mode. Otherwise, they are completely suppressed.
Added player_consume, projectile_hit, and some new 1.5 abstraction.