Add new blocks and items for Minecraft 1.9 compatibility. Closes GH-19

[deathcap]

https://github.com/deathcap/ProgrammerArt/issues/19

http://minecraft.gamepedia.com/1.9#Blocks

• [x] Beetroots
• [x] Command block sides
• [x] Command block chain
• [x] Command block repeating
• [x] Chorus flower
• [x] Chorus plant
• [x] Debug
• [x] End rod
• [x] End stone brick
• [x] Frosted Ice
• [x] Grass path
• [x] Purpur block
• [x] Purpur pillar
• [x] Redstone dust dot line
• [x] Structure block
• [x] Water overlay

http://minecraft.gamepedia.com/1.9#Items

• [x] acacia_boat
• [x] banner_base
• [x] banner_overlay
• [x] beetroot
• [x] beetroot_seeds
• [x] beetroot_soup
• [x] birch_boat
• [x] broken_elytra
• [x] chorus_fruit
• [x] chorus_fruit_popped
• [x] clock_00 - clock_63
• [x] compass_00 - compass_31
• [x] dark_oak_boat
• [x] door_acacia
• [x] door_birch
• [x] door_dark_oak
• [x] door_jungle
• [x] door_spruce
• [x] dragon_breath
• [x] elytra
• [x] empty_armor_slot_shield
• [x] end_crystal
• [x] fireworks_charge_overlay
• [x] jungle_boat
• [x] leather_boots_overlay
• [x] leather_chestplate_overlay
• [x] leather_helmet_overlay
• [x] leather_leggings_overlay
• [x] oak_boat
• [x] potion_bottle_lingering
• [x] potion_overlay
• [x] spawn_egg_overlay
• [x] spectral_arrow
• [x] spruce_boat
• [x] tipped_arrow_base
• [x] tipped_arrow_head

Pack

• [x] Update json version