I think the new pay command has proven itself in the last 18 months!
Also various pay tests took "compat" then didn't use it, so clean them
up.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Changelog-Removed: JSON-RPC: `legacypay` (`pay` replaced it in 0.9.0).
Any file in this directory which is executable and whose name only
consists of alphanumeric characters, space, '.', '-' or '_' will be
automatically loaded when lightningd starts (unless suppressed with
commandline options).