added smd tantalum capacitors http://www.digikey.com/Web%20Export/Supplier%20Content/Kemet_399/PDF/Kemet_TantalumSMCap.pdf
new formula to calculate silks offset
added smd version of double row pinhead (PLD-xxS, PLD-xxT, PLD2-xxS, PLD2-xxT, PLLD-xx), still not sure about dimensions