Fixed Synth output bug

should fix jakimfett/minechem#325
Updates stone and cobblestone recipes for Synth (Fixes jakimfett/minechem#330)
Stone Recipe: 16 stone for SiO2 and Al2O3
Cobblestone recipe: 16 cobble for Si2O4
Added AlO as a decomp chance from stone
16 stone will on average decomp 0.45Si, 3.2O and 0.45Al, which prevents any easy duping