[1.7] Custom blockshapes are no longer supported

Verification builds:
1.7.0.2 Release 1117901

Summary:
Blockshapes have been removed from the blocks.json and are no longer supported 

Impact:
This affects the Tiny Footprints and Adventure's Dream texture packs. 

Repro Steps:

1. Download the Tiny Footprints texture pack from the Store
2. Create a new world with the Equip the pack and have Cheats enabled 
3. Collect sand, dirt, a water bucket, a potato, sugar cane and a hoe from the Creative menu
4. Create a 1x1 hole and place water in it. Make sure sand and dirt surround the water
5. Hoe the dirt and place the potatoes on the farmland, and place the sugarcane on the sand
6. Observe the blockshape 
7. Repeat in a 1.6 build and observe the blockshapes displaying as intended 

Observed Results: 
Custom blockshapes have been removed and thus some textures no longer have the correct designed appearance.

Expected Results: 
Custom blockshapes are continued to be supported 

Screenshots/Videos attached: 
Yes

Regression Build:
1.6 builds. Confirmed in 980905