Remove the need of lwt.syntax
ocp-indentize the code
Reduce the number of allocations by returning `return_unit` instead of `return ()`

`return_unit` is pre-allocated so it's a no-op. `return ()` allocates a new block every time.
Style
Shorten some long lines
More style fixes
Remove trailing spaces
More style fixes
Remove dead-code
spaces
spaces
Remove unnecessary ignore
Remove warnings (and dead code)
Simplify the code to create low-level server/client connection

Now all the state needed for creating a connection is in a record
Add .merlin file
More styling fixes
More styling fixes
clean-up the segment API
Cut input_no_pcb into chunks

Now, each TCP message kind has its own `process` function.
More style fixes in Segment/Tcb