Replaced persistence layer with JSON instead of serialization.
Revert "Replaced persistence layer with JSON instead of serialization."

This reverts commit d9ce2bf2bb7fc727767b5171899ac6d4c856181a.
Replaced dispenser persistence with JSON instead of serialized HashMap.
The reasons for doing this are two fold. First, Location is not
serializable by default, so for each Location we have, we had to create
a SerializableLocation and add that to a new HashMap. This obviously
increases memory usage and processing time to load/save. 

Second, with JSON as the backend, we are able to rely less on the
implementation of a class. For an update to Minecraft/Bukkit or the
plugin, with using getters instead of serialized classes, we do not have
to worry about implementation changes breaking persistent data.