Add: support names in creaturetarget (eg. pig~Fred: [{drop: apple}])

* doesn't yet support other creature data alongside (eg. pig@baby~Fred will fail)
Fix: potioneffects will now renew an existing potioneffect

* previously if the player already had an effect the duration would not renew, removing any identical effects before adding the new one fixes this
Minor: fix a compiler warning in ConfigurationNode - makes the intended purpose more obvious