Also fixes minor bug in blockr data read.
Modifies schedule syntax to include complete/incomplete flag, so if
restart is chosen then the schedule is continued from the first
incomplete transaction in the sequence.
Refactor parsers into separate module (more code reuse to do).
Add a tumbler schedule generator in jmclient/schedule.py.
Alter syntax of schedules; taker interprets fractional amounts
as percentage of mixdepth (for tumbler), and integers as satoshi,
zero still sweep.
TODO tumbler is only a minor delta from sendpayment, fold them together.
