Leash Upgrade

Component name: `leash`. Callbacks:

Tries to put an entity on the specified side of the device onto a leash.

Unleashes all currently leashed entities.

Components	Category	Documentation
Components	Core Components	3D Printer - Abstract Bus - Access Point - Chunkloader - Computer - Crafting - Data Card - Database - Debug - Drone - Drive - EEPROM - Experience - Filesystem - Generator - Geolyzer - GPU - Hologram - Internet - Inventory Controller - Leash - Microcontroller - Modem - Motion Sensor - Navigation - Net Splitter - Piston - Redstone - Redstone in Motion - Robot - Screen - Sign - Tank Controller - Tractor Beam - Transposer - Tunnel - World Sensor
	Others	Component Access - Signals
	Cross-Mod Integration	Applied Energistics

Component/leash