Version 20180607-snapshot for Minecraft 1.12.x

• Changed wand to special sword item
• Added creative tab with wand + other useful items
• Fixed division by zero in /cfill and /cclone
• Fixed tab completion in /cfill, /cclone and /cstack
• Fixed input validation for /cstack and /cselect
• Fixed wand not left clicking air
• Added render overlay for selection