Update ItemNames.java

Double Slabs item form are being removed.

Added Wet Sponge

Trapdoor is now known as 'Wooden Trapdoor'
Added some 1.8 item types.

Double Slabs item form are being removed.
Added Wet Sponge
Trapdoor is now known as 'Wooden Trapdoor'
Other 1.8 item names.
Added more item data support
Reverted double slab removal change
Merge pull request #16 from DoctorDark/master

Data support / 1.8 item types