Fixed broken carpet handler [SEE DESC]

Made BlockHandler pass on control to carpet handler
Declared thinggummies in carpet handler
Fixed carpet block pushback using incorrect format
Fixed longstanding issue with slabs

Fixes FS#298
Changed comments to be more accurate
Fixed lighters replacing blocks
Double slabs work *choke choke*
Fix VSProject path issue
Fixed incorrect double slab drops
Fixed final slab bug

This bug allowed a double slab to be made below by placing a compatible
slab on a "top" slab. The coordinates are always one lower, so now it
checks to see if the slab orientation can be made into a double.
Added comments and fixed a bug

Bug was placing slabs between slabs not making a double slab.
Fixed inconsistent metas and added snow metas
Vines now spread when updated
Redstone fixes [SEE DESC]

Fixed pistons not correctly powering down
Fixed dispensers not correctly powering down
Fixed droppers not correctly power down
Fixed TNT not correctly powering up
Fixed redstone lamps not correctly powering up
Fixed redstone lamps not correctly powering down
Fixed public thing in ClientHandle
Fixed iron door opening by hand
Merging in tigerw's changes from PR #118