Rework serialization primitives to use class structures (e.g. CompactSize, FlatData, VarInt, etc.).
Change Script serialization to not include CompactSize prefix (overall simplification to the code which uses Script).
Bug: leftover untested code in transaction initialization reference local variable which no longer exists.
Simplify update() method for nop-hasher, in the process fixing py3k issues.
Import special ‘tuple’ class to be used as base type.