Bukkit

Added:

• cancel command
• give command
• moved sub commands in sub classes
• tab complete for commands
• implemented api

Changes:

• translated en_US, thanks to @Dragon0697
• renamed middle backpack to medium

Fixed:

• config missing locale value
• Backpack#hasContent is now also checking unuseable items
• item stacking when crafting more than two at the same time
• error when backpack was saved with a null type
• Backpack#hasContent throw error when inventory was null