- change name and type of commitment to network size of a transaction to match the rest of the system and imply its multiplier.  Additionally changed to a VLQ encoded unsigned int.
- change name and type of commitment to the cpu usage for the context_free portion of a transaction to match the rest of the system and imply its multiplier.  Additionally changed to a VLQ encoded unsigned int.
- exposed VLQ encoded unsigned int and ZigZag encoded signed integer types to the ABI built-ins as "varuint32" and "varint32" respectively
- Fixed the unit tests that broke as a result of the above