* Add few missing top level raises Defect in uTP
- Add top level {.push raises: [Defect].}
- remove some local raises, including some unneeded
CatchableErrors.
- Don't export messageHandler (avoiding annoying naming collisions)
- export utp_router as those connection callbacks are in the API
* Add some missing copyright clauses
* Some ident and max line length cleanup
* Rename utp_discv5_protocol.nim to be more consistent
* Add separate datastructure to keep track of window
* Asynchronously block write until until new space in snd buffer
* Introduce write loop
* Properly handle write cancellation
* Proper handling of sending fin packet
* Reset remote window after configured amount of time
* Refactor tests and move socket to separate file
* Move sockets handling to separate class
* Abstract over underlying transport
* Fix bug with receiving duplicated SYN packet
* Fix race condition in connect
KonradStaniec
Kim De Mey