SwapHash used to be a key in the sweeps table. Now the key is outpoint which
replaces columns outpoint_txid and outpoint_index. In-memory structures and unit
tests were also updated to use outpoint as key. Outpoint is truly unique.
This commit fixes faulty timestamps caused by using unix milliseconds
as unix seconds on startup.
This commit also adds a test for the lightning-terminal issue that first
reported the bug.
This commit adds a postgres store to the loopdb package.
Ths postgres migrator uses a replacer filesystem to replace the
sqlite types to postgres types in the migration.
