Better control of gas accounting

[feliam]

Add evm.gas configuration constant/variable/thing to control how to account gas. For example "static" will ignore all dynamic calculated fees. (This is different from evm.oog. The latter controls how and when to check for Out Of Gas)

Change rpl -> rust-rpl dependency.

[ehennenfent]

@feliam were you still hoping to merge this? I think those couple of nits are the only things blocking it.