Payment channel implementation sketch Simplifications: - unidirectional paychans - no top ups or partial withdrawals (only opening and closing) TODO - chnge module name to "channel"? - Find a better name for Queue - clarify distinction between int slice and abstract queue concept - refactor queue into one object - Do all the small functions need to be methods on the keeper or can they just be floating around? - Tidy up - standardise var names, method descriptions, heading comments - is having all the get functions return a bool if not found reasonable? - any problem in signing your own address? - Gas - Codespace - find nicer name for payouts