The numerous tor conditional compile flags were removed by
extracting transport creation to the main statement. A tor
transport is created if Alice specifies a tor port using the CLI.
Add a binary crate `swap` that implements two nodes (Alice and Bob). With this
applied we can start up a node for each role and do:
- Bob: Requests current amounts using BTC is input
- Alice: Responds with amounts
- Bob: (mock) get user input to Ok the amounts
... continue with swap (TODO)
