add faster encodings for common types
add faster encodings for common types

MrStrong/Sia,NebulousLabs/Sia,NebulousLabs/Sia,mharkus/Sia,ChrisSchinnerl/Sia,mtlynch/Sia,ericflo/Sia,MrStrong/Sia,mtlynch/Sia,mharkus/Sia,ChrisSchinnerl/Sia,ericflo/Sia