Gas charging parameters for FIP-0032

[Kubuxu]

Name	Value	Notes
Execution Gas	0.6 ns/op = 6gas/op
Syscall Cost	5000 op = 30000 gas	Applicable for every syscall
Externs Cost	1µs = 10000 gas	Applicable for every extern call
block_open	OnIPLDRead + extern cost + syscall cost
block_read	0 + syscall cost
block_write	0 + syscall cost
block_link	OnIPLDWrite + syscall cost
block_stat	0 + syscall cost
get_chain_randomness	+ extern cost + syscall cost
get_beacon_randomness	+ extern cost + syscall cost
verify_consensus_fault	+ extern cost + syscall cost

[raulk]

Action items

• Simulation/backtesting of new gas model on relevant nv15 messages.
• Submit update to FIP-0032.

[raulk]

See filecoin-project/FIPs#368 for final parameters proposal.