Merge pull request #63 from basicmark/master

Added region commands.
Added feature to automatically add treasures to a group. (will be replaced with book-config feature later)
Read [this](https://github.com/Mtihc/TreasureChest/pull/63) for more info
Removed parameter 'shared' from TreasureChest constructor

Also combined methods 'treasureSet' and 'treasureSetShared', at
TreasureManager. Since they were almost identical.
Created Facade interface for repositories etc

New interface ITreasureDataFacade combines a bunch of interfaces. It's
implemented by TreasureDataFacade, which is extended by TreasureManager.
This results in 1 clear interface for loading/saving treasures and
groups, etc. It also cleans up the TreasureManager class greatly.

Also created base classes  YamlRepository<K> and Repository<K, V> to
replace GroupRepository and LocationRepository.
Rest of the code uses new interface

Still not sending load/save errors to the player...
Added TreasureException to replace getError method of TreasureChestGroup

Still not sending load/save errors to the player. Will add setTreasure,
getTreasure, etc. With throws IOException, InvalidConfigurationException
soon.
Removed some leftover variables and imports from TreasureManager
Moved around some packages

plugin.util became util, so
plugin.util.commands became util.commands, and
rewardfactory.rewards.prompts became util.prompts

The reason is that these packages deserve to be in a higher namespace.
Since they don't reference any other packages.
Fixed packages names and imports since last commit
Added alot of Javadocs
use-meta-data command is deprecated

Planning to implement the book-config feature
https://github.com/Mtihc/TreasureChest/issues/65
Fixed command /tchest ?

Added alias "help" for "?"
Fix region NULL pointer access in region commands