One last release before the "big release"

The next release will contain breaking changes. If you'd rather stick to the old (and trusted?) rebalance-lnd, this is for you.

Most interesting and somewhat recent changes:

• bugfix: the previous code ignored the wrong "high fee" channel when using --econ-fee, causing suboptimal routing attempts
• bugfix: you can now select a random channel as the first hop (-f -1)
• bugfix: with --econ-fee the last hop is ignored less often, and only when intended
• bugfix: with --econ-fee the second hop may now be ignored when it is too expensive
• there's an economy fee mode (--econ-fee, have a look at the readme!)
• ignore more channels before even attempting to find a route (to avoid routes that will end up being too expensive anyway)
• fixed minor typo in readme (#180, thanks @GlenCooper!)
• fee rates for --econ-fee computation are capped at 2,000ppm (before: 1,000ppm)