Multiple fixes.

Fixed indenting in pom.xml.
Updated ProtocolLib dependency to 3.4.0.
Changed CraftBukkit dependency to Bukkit as it was causing false
Deprecation messages to pop up.
Updated Bukkit dependency to 1.7.10-R0.1-SNAPSHOT.
Fix SELL NPC interaction.
Fixed ExchangeHandler returning null.
Fixed ExchangeHandler.getPlayerName() returning null.
Fixed KIT NPC interaction throwing an NPE.